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Magnetite

Magnetite is a common iron oxide mineral with the chemical formula Fe₃O₄, consisting of iron(II) and iron(III) ions in a 1:2 ratio, and it is the most magnetic naturally occurring mineral on Earth.^[1] Belonging to the spinel group, it features an inverse cubic crystal structure where tetrahedral sites are occupied by Fe³⁺ ions and octahedral sites by a mix of Fe²⁺ and Fe³⁺ ions, making it ferrimagnetic and capable of forming permanent magnets; naturally magnetized specimens are known as lodestone.^[2]^[3] It typically appears as black, opaque, octahedral crystals or massive aggregates with a metallic to submetallic luster, a black streak, and a Mohs hardness of 5.5 to 6.5.^[4]^[5] As one of the primary sources of iron ore, magnetite is economically vital and occurs abundantly as an accessory mineral in igneous and metamorphic rocks, as well as in sedimentary environments like banded iron formations.^[6]^[7] Large deposits are found in regions such as Australia, Sweden, and the United States, often formed through magmatic segregation, hydrothermal processes, or contact metamorphism.^[8] Its high iron content (up to 72.4% Fe) and magnetic separability make it a key raw material for steel production worldwide.^[9] Beyond iron extraction, magnetite has diverse industrial applications, including use as a dense medium in coal washing and mineral processing,^[10] a black pigment in paints and coatings for high-temperature environments,^[11] and a component in water filtration systems^[12] and magnetic recording media.^[11] It also plays roles in environmental remediation due to its reactivity with contaminants^[13] and in biomedical research for magnetic nanoparticle applications.^[14] Biogenic magnetite, produced by certain organisms like magnetotactic bacteria, aids in navigation and is studied for its role in biological magnetism.^[2]

Properties

Crystal Structure

Magnetite has the chemical formula Fe₃O₄ and adopts an inverse spinel structure, which is a key feature enabling its distinct properties.^[15] This structure belongs to the cubic crystal system with space group Fd3m (No. 227).^[16] The lattice parameter is approximately 8.39 Å, as determined from X-ray diffraction studies.^[17] In the inverse spinel arrangement, oxygen anions (O²⁻) form a close-packed face-centered cubic (FCC) lattice, providing the anionic framework.^[18] Iron cations occupy interstitial sites within this oxygen lattice: specifically, Fe³⁺ ions fill all tetrahedral (A-site) positions and half of the octahedral (B-site) positions, while Fe²⁺ ions occupy the remaining octahedral sites.^[15] This distribution results in a formula representation of Fe³⁺[Fe²⁺Fe³⁺]O₄, where square brackets denote octahedral coordination. The unit cell of magnetite contains eight formula units (Z = 8), comprising 32 oxygen atoms arranged in the FCC sublattice, eight tetrahedral sites, and sixteen octahedral sites.^[19] The tetrahedral sites are corner-sharing Fe³⁺O₄ tetrahedra, while the octahedral sites form edge-sharing FeO₆ octahedra, creating a three-dimensional network that stabilizes the overall cubic symmetry.^[20] This interstitial cation placement within the oxygen framework is characteristic of the spinel structure type, distinguishing inverse spinels like magnetite from normal spinels where divalent cations occupy tetrahedral sites.^[21]

Physical Characteristics

Magnetite typically exhibits a black or greyish-black color with a metallic to sub-metallic luster, rendering it opaque in appearance.^[16]^[22] Its streak is black, aiding in its identification during mineral testing.^[16]^[22] The mineral has a Mohs hardness ranging from 5.5 to 6.5, making it moderately hard and resistant to scratching by common tools like a knife.^[16]^[22] Its specific gravity is approximately 5.2, indicating a high density that contributes to its weighty feel compared to many other minerals.^[22]^[23] In terms of crystal morphology, magnetite commonly forms octahedral habits, though dodecahedral and massive forms also occur; twinning is rare and typically follows the spinel law when present.^[16]^[22] Grain sizes vary widely, from microcrystalline inclusions in fine-grained igneous and metamorphic rocks to large crystals reaching several centimeters in pegmatites.^[24]^[25] Magnetite's melting point is 1,597 °C, while its boiling point is approximately 2,623 °C, reflecting its stability at high temperatures relevant to geological processes. It lacks cleavage, instead displaying a subconchoidal to uneven fracture when broken.^[22]^[6]

Chemical Properties

Magnetite has the chemical formula Fe₃O₄, which corresponds to a stoichiometric composition of approximately 31.03 wt% FeO and 68.97 wt% Fe₂O₃, yielding an overall iron content of 72.36 wt%.^[22] This mixed oxide structure reflects the mineral's inverse spinel arrangement, where iron exists in mixed oxidation states: one Fe²⁺ ion in tetrahedral coordination and two Fe³⁺ ions in octahedral sites.^[19] The presence of both Fe(II) and Fe(III) enables rapid electron hopping between adjacent octahedral sites, a process that underlies magnetite's semiconducting behavior and facilitates charge transfer in various geochemical reactions.^[26] In terms of reactivity, magnetite is relatively stable but undergoes oxidation to hematite (Fe₂O₃) when exposed to air at elevated temperatures above approximately 500°C, a transformation driven by the loss of Fe²⁺ and incorporation of oxygen.^[27] Under reducing conditions, such as those involving hydrogen or carbon monoxide, it can be reduced stepwise to wüstite (FeO) and eventually to metallic iron.^[28] Magnetite is insoluble in pure water across a wide pH range but readily dissolves in strong acids like hydrochloric acid (HCl), releasing Fe²⁺ and Fe³⁺ ions into solution.^[29] Magnetite demonstrates high stability under diverse geological conditions, persisting in igneous, metamorphic, and sedimentary environments up to temperatures of 800–1000°C and pressures relevant to the Earth's crust.^[30] In hydrothermal settings, it can undergo alteration through fluid-rock interactions, including partial oxidation or dissolution-reprecipitation, yet remains a dominant phase in many ore-forming processes.^[31] Natural samples frequently incorporate impurities via cation substitution, such as Ti⁴⁺ replacing Fe³⁺ (up to several wt% in titanomagnetite) or Mg²⁺ for Fe²⁺, which modifies its lattice parameters and stability.^[32] Isotopic variations, notably in oxygen (δ¹⁸O ranging from -5‰ to +15‰) and iron (δ⁵⁶Fe from -1‰ to +1‰), record environmental conditions during formation, with heavier values often indicating hydrothermal or magmatic origins.^[33]

Magnetic Properties

Magnetite displays ferrimagnetic behavior below its Curie temperature, characterized by the antiparallel alignment of magnetic moments between Fe³⁺ ions in tetrahedral sites and a mixture of Fe²⁺ and Fe³⁺ ions in octahedral sites within its inverse spinel crystal structure, leading to a net magnetization from uncompensated spins on the octahedral sublattice.^[34] This ferrimagnetic ordering results in a saturation magnetization of approximately 480 emu/cm³ at room temperature, reflecting the strong exchange interactions that stabilize the aligned spins.^[35] The material's low coercivity, around 100 Oe, classifies it as a soft magnet, enabling easy reversal of magnetization with minimal energy loss.^[36] The Curie temperature of magnetite is 580 °C, above which thermal agitation disrupts the ferrimagnetic order, transitioning the material to a paramagnetic state with no spontaneous magnetization.^[37] At lower temperatures, magnetite undergoes the Verwey transition near 125 K, where charge ordering between Fe²⁺ and Fe³⁺ ions on octahedral sites causes a structural distortion from cubic to monoclinic symmetry and a sharp increase in electrical resistivity by several orders of magnitude.^[38] This transition also affects magnetic properties, with a drop in magnetization and changes in susceptibility observed in low-temperature measurements. Hysteresis loops for bulk magnetite are narrow and symmetric, indicative of its soft magnetic nature, with low remanent magnetization (typically 10-20% of saturation) and a small area representing minimal hysteresis loss during magnetization cycles.^[39] Magnetic susceptibility measurements reveal high values, often exceeding 10 in SI units for pure samples, decreasing gradually with increasing temperature and showing anomalies near the Verwey transition due to altered spin dynamics.^[40] These properties make magnetite a model system for studying ferrimagnetism in transition metal oxides.

Occurrence and Formation

Geological Deposits

Magnetite is a common accessory mineral in the Earth's crust, forming through a variety of abiotic processes in igneous, metamorphic, and sedimentary environments, which contribute to its widespread distribution and economic significance as an iron ore.^[41] In igneous settings, magnetite crystallizes early during the fractional crystallization of mafic and ultramafic magmas, often forming thick, monomineralic layers in large layered intrusions. A prime example is the Bushveld Complex in South Africa, where the Main Magnetite Layer in the Upper Zone consists of massive magnetite accumulations up to several meters thick, resulting from density-driven settling and magma replenishment events that concentrate iron-titanium oxides.^[42] These layers can host vanadium- and titanium-rich magnetite, enhancing their resource value.^[43] Metamorphic environments, particularly contact metasomatic zones and regional metamorphism, produce significant magnetite concentrations through reactions involving iron-bearing fluids and host rocks. In skarn deposits, magnetite forms via interaction between intrusive magmas and carbonate-rich sediments, yielding massive ore bodies with high iron content, as seen in calcic skarns where fluid-rock exchange promotes oxide precipitation.^[44] Banded iron formations (BIFs), ancient sedimentary sequences altered by high-grade metamorphism, host vast magnetite resources; for instance, prograde reactions at 800–900 °C convert iron silicates and carbonates into magnetite-quartz assemblages, with textures indicating fluid-mediated recrystallization.^[45] Sedimentary deposition of magnetite occurs primarily in ancient marine basins during periods of high oceanic iron availability, often as authigenic crystals or detrital grains in anoxic conditions. In BIFs, such as those in the Archean and Paleoproterozoic eras, magnetite precipitates from ferrous iron-rich waters oxidizing upon upwelling, forming alternating oxide-silica bands that represent chemical sediments rather than clastic deposits.^[46] Microbial mediation can further enhance magnetite formation in modern analogs through dissimilatory iron reduction, producing fine-grained crystals in methanic sediments.^[47] Globally, magnetite dominates many of the largest iron ore reserves, with total iron ore resources exceeding 800 billion tonnes, a substantial portion of which is magnetite-bearing, primarily in BIFs and igneous complexes.^[41] Notable deposits include the Kiruna iron-oxide-apatite (IOA) orebody in Sweden, originally containing approximately 2 billion tonnes of high-grade ore and the world's largest underground magnetite mine, with current resources exceeding 1 billion tonnes (including the 2024 Per Geijer extension) at depths up to 2 km.^[48]^[49] In the United States, the Iron Mountain deposit in Wyoming exemplifies metamorphic magnetite in Precambrian BIFs, while Australia's Pilbara Craton hosts extensive BIF-hosted magnetite resources, such as at Mount Tom Price, with original estimates around 900 million tonnes of high-grade ore.^[50] Magnetite ores are frequently intergrown or paragenetically associated with hematite and ilmenite, forming solid solutions or exsolution lamellae that influence ore processing; for example, ilmenite-magnetite intergrowths in igneous rocks arise from high-temperature equilibration, while hematite may pseudomorph after magnetite via oxidation.^[51] Economically viable deposits typically contain greater than 30% iron, though lower-grade BIF ores (20–30% Fe) are beneficiated through grinding and magnetic separation to achieve concentrates exceeding 65% Fe.^[52]^[53] Exploration for magnetite deposits relies heavily on geophysical methods, particularly aeromagnetic surveys that detect pronounced magnetic anomalies due to magnetite's high magnetic susceptibility, which can delineate buried orebodies over large areas.^[54] These anomalies, often exceeding several hundred nanoteslas, guide drilling targets in regions like the Pilbara or Bushveld, where magnetite contrasts sharply with surrounding non-magnetic host rocks.^[55]

Biological Occurrences

Magnetotactic bacteria, such as those in the genus Magnetospirillum, biomineralize chains of magnetite crystals within specialized organelles called magnetosomes to facilitate navigation along geomagnetic field lines in aquatic environments.^[56] These crystals typically measure 35–120 nm in length, ensuring they remain in the single-magnetic-domain state for optimal magnetic alignment without thermal fluctuations disrupting their orientation.^[57] The intracellular biomineralization process occurs within membrane-bound vesicles that nucleate and control crystal growth, size, and chain alignment through specific proteins like Mms6 and Mms7, which regulate morphology and prevent aggregation.^[58]^[59] In higher organisms, biogenic magnetite serves structural and sensory roles. Chitons, marine mollusks in the class Polyplacophora, incorporate magnetite into their radular teeth to enhance hardness and wear resistance for scraping algae from rock surfaces.^[60] The mineral forms as nanorods in the tooth cusps, providing mechanical strength superior to many synthetic materials.^[61] In birds, magnetite crystals in the upper beak, detected via the trigeminal nerve, contribute to a magnetic "map" sense for positional navigation during migration, potentially interacting with light-dependent cryptochrome mechanisms in the retina for compass orientation.^[62] Similarly, fish such as sockeye salmon (Oncorhynchus nerka) produce single-domain magnetite particles throughout their lifecycle in cranial tissues, enabling detection of Earth's magnetic field for homing and migration.^[63] Biogenic magnetite has also been identified in the human brain, primarily as nanoscale crystals aggregated into chains or clusters within the dura mater and other tissues.^[64] These particles, estimated at 5–100 million per gram of tissue, exhibit single-domain properties suitable for magnetic interactions.^[64] Studies from the 1990s onward, including behavioral experiments and neuroimaging, suggest a potential role in magnetoreception, with evidence of subconscious responses to geomagnetic rotations influencing decision-making and spatial perception.^[65]^[66] Recent findings link elevated magnetite levels in the brain to neurodegenerative conditions; for instance, magnetite nanoparticles from air pollution have been associated with amyloid-β plaque formation and oxidative stress in Alzheimer's disease models, exacerbating neuronal damage.^[67]^[68] This magnetic material may subtly aid orientation by aligning with external fields, though its sensory function in humans remains under investigation.^[69]

Synthetic Production

Magnetite can be synthesized through various laboratory and industrial methods to meet demands for high-purity materials and specific particle sizes not readily available from natural sources. One of the most common wet chemical approaches is co-precipitation, involving the simultaneous precipitation of iron(II) and iron(III) salts, typically in a 1:2 molar ratio, under alkaline conditions at pH 8–12 using bases like sodium hydroxide or ammonia.^[70] This method produces superparamagnetic magnetite nanoparticles with sizes ranging from 5 to 50 nm, offering advantages in simplicity, low cost, and scalability for biomedical and research applications.^[71] Thermal decomposition of iron precursors, such as iron oleate or acetylacetonate complexes, in high-boiling solvents like octadecene at temperatures around 300°C, yields monodisperse magnetite nanocrystals with precise size control.^[72] Hydrothermal synthesis, conducted in sealed autoclaves under elevated temperatures (120–200°C) and pressures, allows for tailored morphologies, including spheres, rods, and cubes, by varying reaction parameters like precursor concentration and additives.^[73] These methods typically achieve purities exceeding 99% for research-grade magnetite, enabling uniform particle distributions essential for advanced applications.^[74] On an industrial scale, magnetite is produced via carbothermal reduction of hematite (Fe₂O₃) using carbon sources like coke or coal at high temperatures (800–1200°C) in rotary kilns, converting the ore to Fe₃O₄ through partial reduction.^[75] Electric arc furnace processes, often applied to iron-rich slags or dusts, facilitate large-scale production by melting and reducing iron oxides in the presence of carbon electrodes.^[76] These techniques yield magnetite with purities of 90–95%, suitable for pigments, heavy media separation, and metallurgy, and can scale to hundreds of tons annually to support bulk demands.^[77] Recent advances since 2020 emphasize green synthesis routes using biomass templates, such as plant leaf extracts from Moringa oleifera or Psidium guajava, which act as reducing and capping agents in co-precipitation or hydrothermal processes to produce eco-friendly magnetite nanoparticles without toxic chemicals.^[78] These biogenic methods enhance sustainability by utilizing agricultural waste, achieving particle sizes below 50 nm while maintaining high purity and biocompatibility for emerging uses.^[79]

Applications

Industrial Uses

Magnetite plays a crucial role in the coal mining industry through dense medium separation (DMS), a process that utilizes a suspension of finely ground magnetite in water to separate coal from denser waste rock. The slurry's specific gravity is typically adjusted to between 1.4 and 1.8, enabling lighter coal particles (with densities around 1.3–1.5 g/cm³) to float while heavier refuse sinks, achieving efficient beneficiation of raw coal feeds.^[80]^[81] This method is preferred for its sharpness of separation and ability to handle large volumes, with magnetite's magnetic properties allowing recovery via drums or high-gradient separators after processing, thus enabling reuse and reducing operational costs.^[82]^[10] In iron and steel production, magnetite is a key raw material for pelletizing, where concentrates of the mineral are formed into uniform pellets suitable for blast furnaces. These pellets, produced by grinding magnetite ore, mixing with binders like bentonite, and firing at high temperatures, provide a high-iron feed (often 65–70% Fe) that enhances furnace efficiency and reduces emissions compared to lower-grade ores.^[83]^[84] Magnetite-based pellets are integral to the blast furnace-basic oxygen furnace (BF-BOF) route, which accounts for about 71% of global crude steel output, highlighting the mineral's foundational role in modern ironmaking.^[85] Magnetite also finds application in water treatment as a dense filter media for removing turbidity and suspended solids from municipal and industrial wastewater. Its high specific gravity (around 5.2 g/cm³) and magnetic recoverability allow for effective filtration in rapid sand filters, where it traps particulates and can be regenerated through magnetic separation or backwashing, extending media life and improving treatment efficiency.^[10]^[86] Historically, magnetite has been employed as an abrasive for polishing metals, stones, and glass due to its hardness (5.5–6.5 on the Mohs scale), though synthetic alternatives have largely supplanted it in modern applications. Additionally, as a source of black iron oxide, it served as a pigment in ancient paints, ceramics, and prehistoric art, providing durable coloration valued for its stability and opacity.^[87]^[88] The economic significance of magnetite in industry is substantial, with global iron ore production exceeding 2.5 billion tons annually, of which magnetite constitutes a significant portion estimated at 500-750 million tons, supporting the iron ore supply chain that underpins much of the world's infrastructure and manufacturing sectors.^[89]

Technological Uses

Magnetite, or Fe₃O₄, played a foundational role in the development of magnetic recording technologies during the mid-20th century. Early audio tapes, such as those used in the German Magnetophon system from the 1930s, employed magnetite particles as the magnetic medium due to their strong ferrimagnetic properties and ability to retain magnetization. These black iron oxide particles were dispersed in a binder on plastic substrates, enabling high-fidelity audio recording and playback, though they were later largely supplanted by gamma-ferric oxide (γ-Fe₂O₃) and other materials by the 1980s for improved stability and density. In early hard disk drives, magnetite-based ferrite particles were similarly utilized in particulate media and heads for data storage, providing reliable magnetic alignment until the shift to thin-film and perpendicular recording technologies in the late 20th century.^[90]^[91] Leveraging its iron-rich structure, magnetite serves as a key catalyst in chemical processes, particularly in syngas conversion. In the Fischer-Tropsch (FT) synthesis, reduced fused-magnetite catalysts facilitate the production of hydrocarbons from carbon monoxide and hydrogen, with the iron sites promoting chain growth and the accompanying water-gas shift reaction; typical activity rates for such catalysts reach up to 0.5 mol CO/g·h under industrial conditions of 200–350°C and 10–30 bar.^[92]^[93] For ammonia synthesis in the Haber-Bosch process, promoted magnetite catalysts, often doubly or multiply promoted with alumina and potassium, enable nitrogen fixation at 400–500°C and 150–300 bar, achieving equilibrium conversions of 15–25% per pass while maintaining high stability.^[94]^[95] As a base material for spinel ferrites, magnetite contributes to electromagnetic applications through its high permeability and low conductivity. Magnetite-derived ferrites, such as Mn-Zn variants, form cores in power transformers, where they minimize eddy current losses and support efficient energy transfer at frequencies up to 100 kHz, with relative permeabilities exceeding 2000. In microwave absorbers, Ni-Zn ferrites based on magnetite structures attenuate electromagnetic interference by combining dielectric and magnetic losses, achieving reflection losses below -10 dB over 8–12 GHz bandwidths in composite forms.^[96]^[97] In recent advancements during the 2020s, magnetite's theoretical half-metallic ferromagnetism—exhibiting 100% spin polarization at the Fermi level due to its inverse spinel structure—has been harnessed for spintronic devices. Epitaxial Fe₃O₄ thin films demonstrate robust spin injection in magnetic tunnel junctions, with spin polarization values approaching 80–90% at room temperature, enabling low-power spin-valve structures for next-generation memory and logic applications.^[98]^[99]

Biomedical and Emerging Uses

Magnetite nanoparticles, particularly those in the size range of 10–20 nm, have gained prominence in magnetic hyperthermia therapy for cancer treatment, where they are injected into tumors and heated using alternating magnetic fields to induce localized hyperthermia and selectively kill cancer cells while sparing healthy tissue.^[100] This approach leverages the superparamagnetic properties of magnetite to generate heat through Néel and Brownian relaxation mechanisms, with specific absorption rates often exceeding 100 W/g under clinically relevant field strengths of 10–20 kA/m.^[101] Clinical trials, including FDA-approved investigational studies for glioblastoma and prostate cancer, have demonstrated feasibility and safety, with phase I/II results showing tumor regression in patients when combined with radiotherapy.^[102] In targeted drug delivery, magnetite nanoparticles serve as carriers for chemotherapeutic agents like doxorubicin, conjugated via surface functionalization such as PEG or chitosan coatings to enable pH-responsive release and magnetic guidance using external fields for precise tumor accumulation.^[103] This magnetofection-like strategy reduces systemic toxicity by concentrating the drug at the tumor site, with in vivo studies in murine models reporting higher intratumoral drug levels compared to free doxorubicin administration.^[104] The biocompatibility of these systems allows for repeated dosing, enhancing therapeutic efficacy in breast and liver cancers. As superparamagnetic iron oxide nanoparticles (SPIONs), magnetite-based formulations function as negative contrast agents in magnetic resonance imaging (MRI), shortening T2 relaxation times to produce hypointense signals that delineate tumors, lymph nodes, and inflammatory sites with high sensitivity.^[105] Clinically approved examples include Feridex (ferumoxides), which consists of dextran-coated magnetite nanoparticles (120–180 nm hydrodynamic diameter) and was FDA-approved for liver lesion imaging before its discontinuation in 2008 due to market factors, though similar agents like ferucarbotran remain in use globally.^[106] These SPIONs offer advantages over gadolinium-based agents by avoiding nephrotoxicity risks, with doses of 0.56 mg Fe/kg enabling clear visualization in preclinical and early clinical settings. Beyond medicine, magnetite nanoparticles facilitate environmental remediation through adsorption of heavy metals such as arsenic, lead, and chromium from contaminated water, achieving removal efficiencies up to 90–99% via surface complexation and magnetic separation for easy recovery.^[107] In water purification processes, functionalized magnetite composites exhibit adsorption capacities exceeding 200 mg/g for pollutants like dyes and antibiotics, outperforming traditional adsorbents due to their high surface area (50–100 m²/g) and reusability over multiple cycles without significant capacity loss.^[108] Emerging applications as of 2025 include magnetite nanoparticles as vectors in gene therapy, where they complex with plasmids or viral carriers like adeno-associated viruses to enable magnetically guided transfection, improving delivery efficiency by 10–20-fold in hard-to-transfect tissues such as the retina and brain.^[109] In tissue engineering, incorporation of magnetite into scaffolds, such as chitosan or gelatin matrices at 5–10 wt%, promotes cell alignment and mechanotransduction via remote magnetic actuation, enhancing osteogenic differentiation in bone regeneration models.^[110] Toxicity studies confirm biocompatibility at concentrations below 100 μg/mL, with minimal cytotoxicity in cell lines like HEK293 and no significant hemolysis or oxidative stress observed in vivo at therapeutic doses.^[111]

Advanced Forms and Research

Magnetene

Magnetene is a two-dimensional form of magnetite (Fe₃O₄), isolated as a freestanding monolayer through exfoliation techniques from bulk magnetite crystals. The material was first reported in 2020 by researchers at Rice University using liquid-phase exfoliation, where bulk magnetite is sonicated in an organic solvent such as isopropyl alcohol to yield thin sheets, including monolayers, that retain the ferrimagnetic order of the bulk precursor. This synthesis method produces stable dispersions of few-layer flakes, with monolayer samples confirmed via atomic force microscopy and transmission electron microscopy. Mechanical exfoliation has also been employed to obtain high-quality, defect-free monolayers for property characterization, enabling studies of its intrinsic behaviors.^[112] The term "magnetene" specifically denotes this single-layer variant, distinguishing it from thicker exfoliated sheets.^[113] The structure of magnetene comprises a single atomic layer of the inverse spinel lattice inherent to magnetite, with a thickness of approximately 0.5 nm corresponding to the interlayer spacing along the exfoliation direction, typically the (111) or (001) plane. The layer features oxygen-terminated surfaces on both sides, which contribute to its stability and unique interfacial properties despite the covalent bonding typical of non-van der Waals materials.^[114] This configuration preserves the octahedral and tetrahedral coordination of iron atoms (Fe²⁺ and Fe³⁺) from the bulk, but quantum confinement alters the local electronic environment, leading to structural robustness under ambient conditions. Magnetene demonstrates room-temperature ferrimagnetism with an enhanced magnetic moment per iron atom compared to bulk magnetite, attributed to reduced coordination and quantum confinement effects that suppress antiferromagnetic coupling. These magnetic attributes position magnetene as a promising candidate for spintronic devices, such as spin valves and magnetic tunnel junctions, where its intrinsic spin-dependent transport could facilitate efficient spin injection and detection at the nanoscale.^[112] Despite its appealing properties, magnetene faces stability challenges due to its high surface reactivity, with a tendency to oxidize to hematene (Fe₂O₃) upon prolonged exposure to ambient oxygen or moisture, potentially degrading its ferrimagnetic order.^[115] This oxidation is mitigated through surface passivation strategies, such as encapsulation in inert solvents during synthesis or coating with protective layers like graphene or polymers post-exfoliation, which preserve the monolayer integrity for device integration.^[116] Ongoing research focuses on optimizing these passivation methods to enhance long-term environmental stability while maintaining the material's ferromagnetic traits. Recent studies (as of 2024) have also explored magnetene's potential in electrocatalysis for oxygen evolution and reduction reactions due to its tailored electronic structure.^[114]

Nanostructured Variants

Nanostructured variants of magnetite, such as quantum dots and nanowires, display pronounced size-dependent superparamagnetic behavior when their characteristic dimensions fall below 20 nm, enabling applications in magnetic recording and sensing due to the absence of hysteresis at room temperature.^[117] In this regime, thermal energy disrupts the alignment of magnetic moments, leading to rapid relaxation times on the order of seconds or less. The transition to a blocked ferromagnetic state occurs below the blocking temperature T_B, approximated by the formula

T_B = \frac{KV}{25 k_B},

where K is the uniaxial magnetic anisotropy constant, V is the particle volume, and k_B is Boltzmann's constant; this relation highlights how reducing size lowers T_B, often to below room temperature for particles around 10-15 nm. Magnetite nanowires, typically synthesized via template-assisted methods or reduction of hematite precursors, exhibit similar superparamagnetism when diameters are confined below 20 nm, with elongated shapes enhancing shape anisotropy and potentially increasing T_B compared to spherical dots.^[118] Core-shell nanostructures, exemplified by Fe₃O₄@SiO₂ particles, address instability issues in bare magnetite by encapsulating the magnetic core with a silica shell, which prevents oxidation and aggregation while improving dispersibility in aqueous environments.^[119] The silica coating, often applied via reverse microemulsion or sol-gel processes, enhances colloidal stability under physiological pH and ionic strengths, making these structures suitable for biomedical contexts where bare nanoparticles would degrade.^[120] Shell thicknesses of 5-20 nm can be tuned to balance magnetic responsiveness with biocompatibility, reducing cytotoxicity and enabling surface functionalization for targeted delivery.^[121] Hybrid magnetite nanostructures integrate Fe₃O₄ with carbon-based materials like graphene or polymers to leverage synergistic properties for energy storage devices. In graphene hybrids, such as Fe₃O₄ nanoparticles anchored on reduced graphene oxide sheets, the high conductivity and surface area of graphene mitigate volume expansion during lithium-ion battery cycling, achieving specific capacities exceeding 800 mAh/g after 100 cycles.^[122] Polymer hybrids, including Fe₃O₄ embedded in conductive matrices like polyaniline or polypyrrole, enhance supercapacitor performance by facilitating pseudocapacitive charge storage, with areal capacitances up to 1.2 F/cm² at scan rates of 5 mV/s.^[123] These composites improve rate capability and cycling stability, as the polymer or graphene buffers mechanical stress from magnetite's phase changes.^[124] Recent research from 2020 to 2025 has advanced the synthesis of magnetite nanostructures using sol-gel methods, which enable precise control over particle morphology and phase purity through hydrolysis and condensation of iron precursors like ferric nitrate in alcoholic solvents, followed by annealing at 300-500°C.^[125] These techniques yield uniform nanoparticles with sizes as small as 8 nm, suitable for exploring topological magnetic properties, including skyrmion-like textures in confined geometries of iron oxide-based nanostructures for low-energy data storage applications.^[126] Investigations into skyrmions in magnetite-based thin films and hybrids have demonstrated their potential for spintronic devices, where topological protection allows stable information encoding, driven by Dzyaloshinskii-Moriya interactions at interfaces. However, key challenges persist in achieving monodispersity, with polydispersity indices often exceeding 0.2 due to nucleation variations, and scalability, as batch processes limit yields to grams while industrial needs demand kilograms without compromising uniformity.^[127] Addressing these via continuous-flow reactors remains an active focus to enable widespread adoption.^[128]

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High-pressure neutron diffraction study of magnetite, Fe3O4 ...
Jun 6, 2022 · FIG. 1. The crystal structure of Fe3O4 in the inverse spinel structure, space group F d 3 ¯ m ⁠. Oxygen atoms are shown as red spheres.
[18]
Magnetite Mineral Data - Mineralogy Database
Magnetite Mineral Data ; General Magnetite Information ; Help on Chemical Formula: Chemical Formula: Fe++Fe+++2O4 ; Help on Composition: Composition: Molecular ...
[19]
Magnetite - Common Minerals
It is one of the most abundant metal oxides, and its crystal structure contains both the ferrous (Fe+2) and ferric (Fe+3) forms of iron ions.Missing: formula | Show results with:formula
[20]
https://link.aps.org/doi/10.1103/PhysRevB.92.075440
[21]
Colorado rare earth pegmatites - Mineralogical Society of America
The wall zone, which is poorly exposed in the main cut, consists of graphic granite, quartz, microcline, and uncommon, one-inch magnetite crystals in a medium- ...
[22]
Iron(II,III) oxide - Wikipedia
Appearance, solid black powder ; Density, 5 g/cm ; Melting point, 1,597 °C (2,907 °F; 1,870 K) ; Boiling point, 2,623 °C (4,753 °F; 2,896 K).
[23]
Electron hopping in magnetite - ScienceDirect.com
It is suggested that the broadening is due to an electron exchange between the Fe 3+ and Fe 2+ ions at the B site.
[24]
Oxidation induced strain and defects in magnetite crystals - PMC - NIH
Feb 11, 2019 · Oxidation of magnetite (Fe3O4) has broad implications in geochemistry, environmental science and materials science.Missing: impurities | Show results with:impurities
[25]
The Characteristics and Reduction of Wustite - IntechOpen
The magnetite is further reduced by gas (CO and H₂) to wustite. All reduction is taking place by means of gas reduction (Fe₂O3 + CO → 2FeO + CO₂), and in this ...
[26]
Hydrothermal Magnetite - GeoScienceWorld
It is well known that at room conditions magnetite dissolves in concentrated HCl at a rapid rate, and that no solubility is measured in pure water. If a ...
[27]
The chemistry of hydrothermal magnetite: A review - ScienceDirect
We present extensive geochemical data for hydrothermal and igneous magnetite. Magnetite chemistry reflects formation conditions and fingerprints mineral ...
[28]
Hydrothermal alteration associated with magnetite mineralization in ...
The pattern of alteration zonation is controlled by either depth or temporal evolution of ore-forming fluids. •. A lack of abundant sulfide minerals is probably ...
[29]
[PDF] The effects of metamorphism on O and Fe isotope compositions in ...
substitute for Fe3+ in magnetite, where the most common substitution is Ti as part of the magnetite–ulvöspinel solid solution that exists at magmatic ...
[30]
Triple oxygen isotope variations in magnetite from iron-oxide ...
Dec 17, 2019 · Oxygen isotope ratios in magnetite can be used to study the origin of iron-oxide ore deposits. In previous studies, only 18O/16O ratios of ...
[31]
Structural and magnetic properties of the Fe 3 O 4 (110) surface
Mar 27, 2025 · The ferrimagnetic configuration of magnetite originates from the dominant antiferromagnetic interaction between T d and O h sites. Magnetite ...
[32]
Magnetic Vortices as Efficient Nano Heaters in Magnetic ... - Nature
Jan 19, 2018 · The saturation magnetization of magnetite nanoparticles equals to the bulk value, M s = 480 emu/cm3, the cubic magnetic anisotropy ...
[33]
[PDF] Magnetoresistance Characteristics in Individual Fe3O4 Single ...
Mar 11, 2015 · around 120 K with a 100 Oe room temperature coercivity and 45 emu/g saturation magnetization, which are comparable to bulk magnetite.
[34]
[PDF] FERROMAGNETIC MINERALS
The resulting saturation magnetization of magnetite is 480 G. (4.8 × 105 A/m) (adjusted to zero thermal energy at 0°K), and the Curie temperature is 580°C.
[35]
Slow oxidation of magnetite nanoparticles elucidates the limits of the ...
Nov 4, 2021 · Magnetite (Fe3O4) is of fundamental importance for the Verwey transition near TV = 125 K, below which a complex lattice distortion and ...
[36]
Magnetic Hysteresis Properties of Magnetite: Trends With Particle ...
Aug 24, 2024 · We have undertaken a systematic micromagnetic study to quantify the magnetic hysteresis behavior of room-temperature magnetite as a function of particle size.
[37]
Magnetic susceptibility and remanent coercive force in grown ...
We measured initial magnetic susceptibility χ 0 in grown and natural magnetite crystals ranging from 0.09 μm to 6 mm in grain size.
[38]
Reserves and Resources of Iron Ores of India – A Perspective
May 1, 2022 · The global iron ore resources have been estimated at over 800 billion tonnes containing more than 230 billion tonnes of Fe (USGS 2021). With ...<|separator|>
[39]
Magnetite layer formation in the Bushveld Complex of South Africa
Jan 20, 2022 · One deposit that has long been used as a laboratory to address the controls on layer formation in layered intrusions is the Main Magnetite Layer ...
[40]
The nature and origin of titaniferous magnetite-rich layers in the ...
Mar 2, 2017 · The nature and occurrence of Ti magnetite-rich layers in the Bushveld Complex is reviewed and the requirements of any satisfactory genetic model ...
[41]
Two-tiered magmatic-hydrothermal and skarn origin of magnetite ...
The magnetite-bearing ore is divided into two distinct types of massive and banded; the latter hosted mainly by magnesian marbles. Both subtypes of the ore ...
[42]
High-grade metamorphism of banded iron formations: the role of ...
Apr 22, 2024 · Magnetite-quartz-orthopyroxene reaction textures were experimentally replicated at 800 and 900 °C and 1000 MPa in a synthetic BIF using isolated ...
[43]
Sedimentary facies of iron-formation - USGS.gov
Its mineralogy and association suggest origin under weakly oxidizing to moderately reducing conditions, but the mode of precipitation of magnetite is not ...
[44]
A novel authigenic magnetite source for sedimentary magnetization
Dec 10, 2020 · The magnetite is interpreted to be a byproduct of microbial iron reduction within methanic sediments with rapidly changing redox conditions.
[45]
Kiruna Iron Ore Mine, Sweden - Mining Technology
Aug 20, 2020 · With an ore body 4km-long, 80m-thick and reaching a depth of 2km, LKAB's Kiruna is the world's largest, most modern underground iron ore mine ...
[46]
Iron Deposits - an overview | ScienceDirect Topics
The Mount Tom Price deposit in the Pilbara Craton of Western Australia is an example of high-grade microplaty hematite ore, with the original resource being 900 ...
[47]
Ilmenite-hematite-magnetite relations in some emery ores
Jun 29, 2018 · Some replacement of magnetite by hematite is noted, but only a minor percentage of the total hematite present has formed in this manner.
[48]
Australian Green Iron Tracker - IEEFA
Australia's magnetite reserves stand at approximately 10.5 billion tonnes, with the majority – nearly 99% – concentrated in South Australia (5.7 billion tonnes, ...
[49]
Iron Ore | Geoscience Australia
Dec 19, 2023 · Magnetite contains 72.4% Fe by molecular weight, which is higher than hematite, but magnetite ores having lower ore grade (generally 20-30% Fe) ...
[50]
Magnetic Method | US EPA
May 27, 2025 · The magnetic method employs a magnetometer to passively measure Earth's magnetic field at points along the earth's surface.
[51]
Magnetics Studies in Mineral Exploration & Mining | Rangefront
Dec 13, 2024 · These variations, or magnetic anomalies, can indicate the presence of ferromagnetic minerals, such as magnetite, hematite, and pyrrhotite, ...
[52]
Ecology, Diversity, and Evolution of Magnetotactic Bacteria
Sep 4, 2013 · Magnetotactic bacteria (MTB) are widespread, motile, diverse prokaryotes that biomineralize a unique organelle called the magnetosome.
[53]
Applications of Magnetotactic Bacteria, Magnetosomes and ... - NIH
Sep 24, 2018 · With only a few exceptions [47,48], the size of magnetosome crystals ranges from 35–120 nm [1,37], placing them in the stable single magnetic ...
[54]
Control of magnetite nanocrystal morphology in magnetotactic ...
Jul 15, 2016 · We describe regulation of magnetite biomineralization through controlled expression of the mms7 gene, which plays key roles in the control of crystal growth ...
[55]
Magnetosome vesicles are present before magnetite formation ... - NIH
We show that magnetosome vesicles exist in the absence of magnetite, biomineralization of magnetite proceeds simultaneously in multiple vesicles, and ...
[56]
[PDF] chiton193.eps - CalTech GPS
Magne- tite possibly serves two biologic functions: in chitons, this mineral hardens the major lateral teeth for scrap- ing surface and embedded algae from hard ...
[57]
Persistent polyamorphism in the chiton tooth: From a new biomineral ...
Jun 4, 2021 · Typical for Cryptochiton type teeth, the core is exposed in a window (wi) in the magnetite layer on the trailing (anterior) face of the tooth.
[58]
Avian magnetite-based magnetoreception: a physiologist's perspective
The aims of the present review are to review the evidence for a magnetite-based mechanism in birds and to introduce physiological concepts in order to refine ...
[59]
Production of single-domain magnetite throughout life by sockeye ...
By the smolt stage, the amount of magnetite present in the front of the skull is sufficient to provide the fish with a magnetoreceptor capable of detecting ...
[60]
Magnetite biomineralization in the human brain - PMC - NIH
Magnetic property data indicate the crystals are in clumps of between 50 and 100 particles. Biogenic magnetite in the human brain may account for high-field ...Missing: 5-10 μm 2020s
[61]
Human Magnetic Reception Laboratory - MagLab - Caltech
May 28, 2020 · Lining up in chains, magnetite crystals formed the physical basis for magnetoreception, acting as compasses to align the bacteria swimming ...Missing: dura 5-10 μm 1990s- 2020s
[62]
Magnetic sense-dependent probabilistic decision-making in humans
Mar 6, 2025 · In this study, we assessed the implication of the GMF in modulating subconscious non-spatial decision-making in human subjects and the underlying mechanism.<|separator|>
[63]
Magnetite pollution nanoparticles in the human brain - PNAS
Sep 6, 2016 · Previous work has shown a correlation between the amount of brain magnetite and the incidence of Alzheimer's disease (AD) (2, 3).
[64]
Tiny magnetic particles in air pollution linked to development of ...
Feb 29, 2024 · Magnetite, a tiny particle found in air pollution, can induce signs and symptoms of Alzheimer's disease, new research suggests.
[65]
Physiological origin of biogenic magnetic nanoparticles in health ...
The discovery of biogenic magnetic nanoparticles (BMNPs) in the human brain gives a strong impulse to study and understand their origin.
[66]
Magnetite nanoparticles synthesized by co-precipitation method
In this work, magnetite nanoparticles were synthesized via the co-precipitation method. For investigating the effect of various precursors on mean size and ...
[67]
Magnetite Nanoparticles: Synthesis and Applications in Optics and ...
Melting point (°C), 1583–1597. Boiling point (°C), 2623. Color, black. Hardness, 5.5. Type of magnetism, ferrimagnetic. Curie temperature (K), 580. Ms at 300 K ...
[68]
Mechanistic Study on Magnetite Nanoparticle Formation by Thermal ...
A nanoparticle formation mechanism is proposed to explain such contrasting morphology. It is based on estimated time scales of different individual steps.
[69]
Shape Tuning of Magnetite Nanoparticles Obtained by ...
Feb 7, 2019 · The morphology tuning was controlled by the temperature of the reaction; the nanoparticles were synthesized via the hydrothermal method at 120°C, 140°C, and ...
[70]
Synthesis and characterization of magnetite nano particles with high ...
Mar 8, 2019 · There are several different methods for production of iron oxide nanoparticles such as coprecipitation, sol-gel, hydrothermal, emulsion- ...
[71]
Kinetic Study on the Carbothermic Reduction from Hematite to ...
A study was conducted on the kinetics of the carbothermic reduction from hematite to magnetite (magnetizing roasting).
[72]
Thermodynamic analysis of the selective carbothermic reduction of ...
When automobile scrap is remelted in an electric arc furnace (EAF) about one to two percent of the charge is converted into a dust, which is commonly referred ...
[73]
Life Cycle Assessment of Magnetite Production Using Microfluidic ...
Apr 21, 2023 · Life Cycle Inventory Data for the Synthesis of MNPs at Laboratory and Industrial Scales. laboratory scale 1 g/h, industrial scale 100 t/a.Missing: day | Show results with:day
[74]
Green synthesis of magnetite (Fe3O4) and hematite (Fe2O3 ... - NIH
Oct 17, 2025 · Considering the limitations of existing synthesis methods, we propose an optimized green protocol to synthesize well-defined magnetite and ...Missing: templates post-
[75]
(PDF) Green synthesis of magnetite (Fe3O4) and hematite (Fe2O3 ...
Oct 22, 2025 · To address these challenges, we developed a truly green, efficient, and economical protocol for synthesizing the nanoparticles smaller than 50 ...
[76]
[PDF] DENSE MEDIUM SEPARATION – AN EFFECTIVE AND ROBUST PRE
The DMS process relies on a medium of specific density (specific gravity) that is between the density of the minerals targeted for separation. The form of the ...<|control11|><|separator|>
[77]
Dense Medium Cyclone Separation of Fine Coal: A Discussion on ...
Aug 24, 2023 · In this calculation, the medium density is 1400 kg⋅m−3, a typical value for coal separation. The separation of particles with a density of 1450 ...
[78]
Magnetite Recovery in Coal Washing by High Gradient Magnetic ...
A research program at the Francis Bitter National Magnet Laboratory has de- monstrated successful recovery of magnetite from mixtures of magnetite and coal.
[79]
Heavy media separation with Magnetite - LKAB Minerals
The industry uses Magnetite to produce dense medium separation slurry for coal washing, mineral processing and recycling of metals and plastics.
[80]
[PDF] Influence of Green Pellet Properties on Pelletizing of Magnetite Iron ...
Magnetite iron ore green pellets are produced by balling moist concentrates to green pellets, which are then dried, oxidized to hematite, sintered, cooled and.
[81]
Iron ore pellets and fines - LKAB
Our iron ore pellets and fines are made from magnetite and have high iron ore content – pellets at around 67 percent concentration and fines over 70 percent.
[82]
Share of EAF route in global steel production likely to rise to 40% in ...
Aug 6, 2024 · The share of the primary blast furnace-basic oxygen furnace (BF-BOF) route in global steel production is projected to shrink to 60% in 2030 from 71% in 2023.
[83]
High Intensity Filter Media - Magnetite Iron Ore - Alibaba.com
Rating 4.6 (89) It has a filtering speed, interception capability, long life cycle and so on. I produced magnetite media, the appearance of spherical, high mechanical strength, ...
[84]
Magnetite & Lodestone | Mineral Photos, Uses, Properties
In the past few decades, synthetic abrasives have filled many of the applications where magnetite was previously used. Other Uses of Magnetite. Small amounts ...
[85]
Characterizing the pigments and paints of prehistoric artists
Oct 13, 2021 · This paper offers a broad and critical overview of current discussions on the potential uses and the characterization of pigments in prehistoryRed Pigments · Black Pigments · Prehistoric Paints (binders...
[86]
[PDF] Iron Ore | 2019 Minerals Yearbook - USGS Publications Warehouse
Sep 17, 2024 · The principal form of iron ore mined in the United States contains hematite and magnetite in varying proportions, averaging 25% to 30% iron (Fe) ...
[87]
[PDF] A Review of Analytical Techniques for Audio Magnetic Tapes - CORE
May 31, 2019 · The most important iron magnetic oxides [34–37] are magnetite (Fe3O4) and maghemite (γ-Fe2O3), as shown in Figure 9. Magnetite is a black ...
[88]
Nina Kalinina and Atsuko Go Back to Basics to Build Magnetic ...
"The very first magnetic tapes used iron, which was replaced with iron rust Fe3O4 for Magnetophon, and shortly after replaced with another iron rust, Fe2O3. The ...
[89]
Intrinsic kinetics of the Fischer-Tropsch synthesis on a reduced ...
Intrinsic kinetics of the Fischer-Tropsch synthesis on a reduced fused-magnetite catalyst | Industrial & Engineering Chemistry Process Design and Development.
[90]
Gasoline Via the Fischer-tropsch Reaction Using the Hot-gas ...
A unique catalyst system of low-pressure drop sheet steel grids coated with a powdered magnetite catalyst was tested for the production of gasoline via the ...
[91]
Optimization of time-proven catalyst boosts conversion and efficiency
Feb 19, 2025 · The Haber-Bosch process revolutionized ammonia production by introducing promoted magnetite catalysts.
[92]
Development and Recent Progress on Ammonia Synthesis ...
Dec 10, 2020 · Although magnetite makes up the majority of industrial ammonia synthesis catalysts, wüstite has gained considerable interest with the highest ...Principles of Catalyst Mechanism · Iron Catalysts · Ruthenium-Based Catalysts
[93]
Microwave absorbing properties of ferrites and their composites
Jul 1, 2021 · These composites should have high absorption intensity, a wide absorption bandwidth, a thin thickness, and finally light weightiness.Missing: transformers | Show results with:transformers
[94]
A review on MnZn ferrites: Synthesis, characterization and applications
MnZn ferrites are a class of soft magnetic materials that have very good electrical, magnetic and optical properties.
[95]
Spin-dependent transport properties of Fe3O4/MoS2/Fe3O4 junctions
Nov 2, 2015 · Magnetite is a half-metal with a high Curie temperature of 858 K, making it a promising candidate for magnetic tunnel junctions (MTJs).
[96]
Electronic properties of half metallic Fe3O4 films - AIP Publishing
Apr 22, 2005 · INTRODUCTION. Half metallic ferromagnetic materials, characterized by 100% spin polarization and having only one spin-subband at the Fermi level ...
[97]
Magnetite nanoparticles: an emerging adjunctive tool for the ... - NIH
Apr 23, 2024 · The applications of MNPs for imaging, drug delivery, and hyperthermia treatment are currently in many clinical trials. Nevertheless, clinical ...
[98]
Magnetic nanoparticles and clusters for magnetic hyperthermia
Oct 18, 2021 · In the ongoing MHT clinical trials for the treatment of brain and prostate tumors, iron oxide nanoparticles are employed as intra-tumoral MHT ...
[99]
Comprehensive understanding of magnetic hyperthermia for ... - NIH
Due to all these therapeutic benefits, MNPs-MH based tumor treatments have recently been translated from the lab to clinical trials, and they have been used ...Missing: FDA | Show results with:FDA
[100]
Magnetic Driven Nanocarriers for pH-Responsive Doxorubicin ... - NIH
We describe a hybrid magnetic nanomaterial as a pH-dependent doxorubicin release carrier. This nanocarrier comprises magnetic iron oxide cores with a diameter ...
[101]
Doxorubicin loaded magnetic gold nanoparticles for in vivo targeted ...
In vivo studies proved that magnetic targeted drug delivery can provide a higher accumulation of drug throughout tumor compared with that delivered by passive ...
[102]
Superparamagnetic Iron Oxide Nanoparticles as MRI contrast ... - NIH
This review aims to summarize the recent progress in the design and preparation of SPIONs as cellular MRI probes, to discuss their applications and current ...
[103]
Superparamagnetic iron oxide based MRI contrast agents - NIH
Two SPIO agents are clinically approved, namely: ferumoxides (Feridex in the USA, Endorem in Europe) with a particle size of 120 to 180 nm, and ferucarbotran ( ...
[104]
Heavy Metal Adsorption Using Magnetic Nanoparticles for Water ...
Magnetic nanoparticles are used for heavy metal adsorption in water purification, showing high adsorption capacity and up to 90% efficiency with reuse.
[105]
Recent advances of magnetite nanomaterials to remove arsenic ...
Nov 9, 2022 · This review gives a recent overview of the potential of magnetite nanoparticles and their composites to treat contaminated water and remove unwanted arsenic ...
[106]
Functionalized Magnetic Nanoparticles for Gene Therapy Applications
Nov 29, 2024 · The use of magnetic nanoparticles enhances the effectiveness of gene transfection by immobilizing carriers at a specific location through the application of an ...
[107]
Biomaterials functionalized with magnetic nanoparticles for tissue ...
Magnetic nanoparticles offer promising avenues for creating tissue precursors, based on magneto-responsive biomaterials/scaffolds. •. Time-dependent ...
[108]
Potential toxicity of superparamagnetic iron oxide nanoparticles ...
A study comparing several metal oxide NPs in vitro demonstrated iron oxide NPs to be safe and non-cytotoxic below 100 µg/ml (41). Another study on normal, glia ...Toxicity Studies · Altered Cellular Responses · Changes In Gene Expression
[109]
Friction of magnetene, a non–van der Waals 2D material - Science
Nov 17, 2021 · We demonstrate the low-friction behavior of magnetene, a non-vdW 2D material obtained via the exfoliation of magnetite, showing statistically similar friction ...
[110]
Computational Engineering of Non‐van der Waals 2D Magnetene ...
Aug 30, 2024 · Magnetene is a bifunctional catalyst with superior performance for OER and ORR than state-of-the-art materials. Engineering of the system ...
[111]
Oxidation-State Dynamics and Emerging Patterns in Magnetite
Jul 21, 2023 · We present a hybrid Monte Carlo/molecular dynamics (MC/MD) method based on iron oxidation-state swapping for accurate atomistic modeling of bulk magnetite.
[112]
Green synthesis of ultrathin 2D nanoplatelets, hematene and ...
Jan 26, 2023 · Here, we describe a green procedure for the liquid exfoliation of natural hematite and magnetite – natural iron ores – obtained from the Greek territory.
[113]
Magnetite (Fe3O4) Nanoparticles in Biomedical Application - MDPI
Dec 3, 2020 · Magnetite (Fe 3 O 4 ) nanoparticles are widely applied due to their biocompatibility, high magnetic susceptibility, chemical stability, innocuousness, high ...
[114]
Synthesis and magnetic properties of single-crystalline magnetite ...
The single-crystalline Fe 3 O 4 nanowires can be directly acquired by deoxidizing single-crystalline α-Fe 2 O 3 nanowires in a reduce atmosphere at 410–430 °C.
[115]
Fe 3 O 4 @SiO 2 Core/Shell Nanoparticles: The Silica Coating ...
In this work, we present the coating regulations of Fe3O4 nanoparticles (NPs) by the reverse microemulsion method to obtain the Fe3O4@SiO2 core/shell NPs.
[116]
Synthesis and Characterization of Hybrid Core-Shell Fe3O4/SiO2 ...
Nonstabilized magnetic nanoparticles do not have colloidal stability under physiological conditions, and they are susceptible to oxidation, which can decrease ...
[117]
Enhanced efficiency of Fe3O4@SiO2 with specific ligand layer in ...
Sep 1, 2025 · We have designed core-shell nanoparticles that enhance the separation efficiency of nucleic acids and genetic material during RT-PCR assays.
[118]
Magnetite Nanoparticles In-Situ Grown and Clustered on Reduced ...
Aug 4, 2022 · Recently, reduced graphene oxide (RGO) has attracted much attention on account of its tremendous electronic conductivity and high surface area.
[119]
Recent Advances in the Application of Magnetite (Fe3O4) in Lithium ...
Given its high abundance, environmental friendliness, low cost and high capacity, magnetite (Fe3O4) emerges as a promising anode material. However, the ...
[120]
Development of hybrid nanodiamonds/magnetite/polymer ...
Jul 2, 2025 · The energy storage capabilities of the systems were assessed under both AC and DC conditions to determine the effects of temperature, charging ...
[121]
Preparation and magnetic properties of magnetite nanoparticles by ...
Magnetite nanoparticles are successfully synthesized via sol–gel method combined with annealing under vacuum using inexpensive, nontoxic ferric nitrate and ...
[122]
Green Sol–Gel Synthesis of Iron Oxide Nanoparticles for Magnetic ...
Methods: In this study, we employed a powdered coconut water (PCW)-assisted sol–gel method to produce magnetite nanoparticles for the first time. A ...
[123]
The 2020 skyrmionics roadmap - IOPscience - Institute of Physics
Current research on skyrmions is mostly focused on magnets with chiral crystal lattices and heterostructures with inversion symmetry broken at interfaces of ...3. Skyrmions Far From... · 9. Spintronics With... · 11. Skyrmions In Multilayers...Missing: magnetite | Show results with:magnetite
[124]
Size Control of Highly Monodisperse Citrate-Stabilized Magnetite ...
Collectively, Ln-assisted synthesis addresses longstanding challenges in magnetite NP coprecipitation, providing a scalable route to high-performance magnetic ...
[125]
Review on Recent Progress in Magnetic Nanoparticles: Synthesis ...
In synthesizing monodisperse magnetic nanostructures, there are some challenges like dipolar interactions, particle surface effects, and size control, etc. are ...