Fact-checked by Grok 2 weeks ago

Strontium aluminate

Strontium aluminate is an inorganic compound with the chemical formula SrAl₂O₄, consisting of strontium, aluminum, and oxygen, and it serves as a base material for advanced phosphors when appropriately doped.^[1] It typically appears as a pale yellow, monoclinic crystalline powder with a molar mass of 205.58 g/mol and a density of 3.559 g/cm³.^[2] Undoped, it exhibits basic luminescent properties, but doping with rare earth ions such as Eu²⁺ (as the luminescence center) and Dy³⁺ (as a co-activator) dramatically enhances its performance, yielding high quantum efficiency, thermal and chemical stability, and non-toxicity.^[3] The most notable feature of europium- and dysprosium-doped strontium aluminate (SrAl₂O₄:Eu²⁺,Dy³⁺) is its persistent luminescence, or long afterglow, which can last over 10 hours at room temperature following excitation by visible or ultraviolet light, emitting in the blue-green spectrum (around 520 nm).^[3] This afterglow arises from a unique energy storage mechanism involving charge trapping and release in the crystal lattice, making it superior to traditional zinc sulfide-based phosphors in duration and brightness.^[4] Its broad excitation spectrum and environmental stability further contribute to its dominance in the persistent luminescence market.^[5] Strontium aluminate phosphors find extensive applications in safety and energy-efficient technologies, including emergency exit signs, traffic markings, watch dials, and luminous paints for highways and airports, where they provide visibility without continuous power.^[3] They are also incorporated into composites for textiles, LEDs, and biological imaging due to their biocompatibility and tunable emission.^[6] Ongoing research explores its potential in radiation dosimetry, mechanoluminescent sensors, and waste immobilization, leveraging its robust chemical properties.^[7]^[8]

Chemical identity

Formula and composition

Strontium aluminate is an inorganic compound primarily represented by the chemical formula SrAl₂O₄.^[9] This formula corresponds to a 1:2:4 stoichiometric ratio of strontium (Sr), aluminum (Al), and oxygen (O) atoms, forming the base structure of the material.^[10] A common variant is Sr₄Al₁₄O₂₅, which features a higher aluminum content and is also utilized in phosphorescent applications.^[11] The elemental composition of pure SrAl₂O₄, based on its molar mass of 205.58 g/mol, consists of approximately 42.6% strontium by mass, 26.2% aluminum, and 31.2% oxygen.^[12] These percentages reflect the atomic weights of the constituent elements: Sr (87.62 g/mol), 2×Al (53.96 g/mol total), and 4×O (64.00 g/mol total).^[13] For the variant Sr₄Al₁₄O₂₅, the composition shifts to emphasize more aluminum and oxygen relative to strontium, though exact mass percentages vary slightly with preparation.^[14] In practical applications, strontium aluminate is often doped with rare-earth elements to enhance its properties; europium (Eu²⁺) serves as an activator at typical concentrations of 1-2 mol%, while dysprosium (Dy³⁺) acts as a co-dopant for improved persistence at 1-3 mol%. For example, the composition Sr₀.₉₅Eu₀.₀₂Dy₀.₀₃Al₂O₄ illustrates a standard doping scheme.^[15] Classified as an aluminate ceramic, it belongs to the family of alkaline-earth aluminates known for their stability and luminescent potential.^[16]

Crystal structure

Strontium aluminate, specifically the compound SrAl₂O₄, adopts a monoclinic crystal structure at room temperature in its undoped form, belonging to the space group P2₁ (No. 4).^[17] The unit cell contains four formula units (Z = 4) and features a three-dimensional framework where strontium ions occupy two inequivalent sites coordinated by oxygen atoms, while aluminum ions form tetrahedral AlO₄ units linked to create a stuffed tridymite-like structure.^[18] Representative lattice parameters for this phase are a ≈ 8.447 Å, b ≈ 8.816 Å, c ≈ 5.163 Å, and β ≈ 93.4°. SrAl₂O₄ exhibits a phase transition to a hexagonal polymorph at elevated temperatures, typically above approximately 650°C, where the stable high-temperature phase has space group P6₃ (No. 173).^[19] This hexagonal structure, with lattice parameters a ≈ 8.926 Å and c ≈ 8.499 Å, consists of a more open framework with channels accommodating the larger Sr²⁺ ions, and it can be stabilized at lower temperatures through compositional modifications or rapid quenching.^[20] Another related phase in the SrO-Al₂O₃ system is Sr₄Al₁₄O₂₅, which forms as an orthorhombic structure with space group Pmma (No. 51) and lattice parameters a ≈ 24.785 Å, b ≈ 8.487 Å, c ≈ 4.886 Å; this phase often appears as a secondary polymorph in syntheses and contributes to structural diversity in strontium aluminate materials.^[21] Doping with rare-earth ions, such as Eu²⁺ substituting for Sr²⁺ at cation sites, introduces lattice strain and oxygen vacancies to maintain charge balance, enhancing structural stability by reducing defect clustering.^[22] Codoping with trivalent ions like Dy³⁺ creates additional defect sites, such as hole traps associated with Sr vacancies, which are stabilized through charge compensation mechanisms and influence the overall crystallographic integrity without altering the primary space group.^[23] These doping-induced defects promote phase purity in the monoclinic structure while minimally shifting lattice parameters, as observed in X-ray diffraction refinements.^[24]

History

Discovery and early research

Strontium was first isolated in 1790 by Irish chemist and physician Adair Crawford, who identified it in the mineral strontianite from lead mines in Strontian, Scotland, distinguishing it from similar alkaline earth elements like calcium and barium.^[25] This discovery initiated systematic explorations of strontium compounds, including early investigations into aluminates as part of broader studies on alkaline earth metal oxides and their ceramic applications in the 19th and early 20th centuries.^[26] The luminescent potential of strontium aluminate remained unexplored until the late 20th century. In 1993, researchers at Nemoto & Co., Ltd. in Japan developed long-persistent phosphors using strontium aluminate as the host material, doped with europium to achieve extended afterglow under excitation by visible or ultraviolet light.^[27] This breakthrough was detailed in a 1994 U.S. patent filed by the Nemoto team, including Yasumitsu Aoki and Takashi Matsuzawa, which described the synthesis of Eu-doped SrAl₂O₄ exhibiting afterglow durations of up to 24 hours and high chemical stability.^[28] Building on this work, Matsuzawa et al. published a key 1996 study in the Journal of the Electrochemical Society on rare-earth-doped SrAl₂O₄, specifically Eu²⁺ and Dy³⁺ co-doping, which produced a green afterglow brighter than conventional zinc sulfide phosphors and persisting for over 10 hours at practical intensities.^[29] The mechanism involved trap levels created by Dy³⁺ that stored excitation energy for gradual release, marking a shift from short-lived phosphors to materials suitable for practical illumination. In the late 1990s, foundational experiments expanded understanding of strontium aluminate's dynamic optical behaviors beyond persistent luminescence. Notably, in 1999, Chao-Nan Xu and colleagues at Kyushu University demonstrated mechanoluminescence in Eu-doped SrAl₂O₄, where mechanical stress induced visible light emission, enabling direct visualization of stress distributions in solids for the first time. These early studies highlighted the material's responsiveness to mechanical and photoexcitation, laying groundwork for advanced luminescent applications.

Commercial development

The commercial development of strontium aluminate phosphors accelerated in the early 1990s with the filing of a key patent by Nemoto & Co., Ltd., which described a long-persistent phosphorescent material based on a strontium aluminate host lattice doped with europium (Eu²⁺) as the activator and dysprosium (Dy³⁺) as the co-activator, branded as LumiNova pigment.^[28] This innovation marked a shift from traditional zinc sulfide-based phosphors to more durable, non-toxic alternatives with afterglow durations exceeding 10 hours, enabling broader applications in safety signage and consumer goods.^[30] Building on this foundation, the 2000s saw the introduction of Super-LumiNova, an enhanced formulation of Eu/Dy-doped strontium aluminate developed through a joint venture between Nemoto & Co. and RC Tritec AG, specifically tailored for high-precision uses in watch dials and emergency safety markings due to its improved brightness and rechargeability under ambient light.^[31] This product line facilitated licensing to global manufacturers, including Swiss watch brands, and established strontium aluminate as the preferred material for non-radioactive luminescence, surpassing earlier radium- and tritium-based alternatives in safety and performance.^[32] The 2010s witnessed significant market expansion driven by demand in automotive, aerospace, and consumer electronics sectors, as manufacturers optimized synthesis for cost-effective, high-volume output.^[33] Key milestones included the adoption of international standards for phosphorescent materials in 2005, such as those aligning with DIN 67510 for pigment testing and performance metrics, which standardized quality assurance and accelerated regulatory approval for commercial products.^[34] By 2023, advancements in mechanoluminescent variants of strontium aluminate—incorporating stress-induced light emission alongside persistent phosphorescence—emerged as a high-impact development, with research demonstrating enhanced sensitivity for real-time structural monitoring in composites and sensors, further broadening commercial potential in smart materials.^[35] As of 2025, the market continues to expand, with projections estimating growth to USD 461.6 million by 2035 at a CAGR of 4.5% for phosphorescent pigments, driven by demand in safety and consumer sectors.^[36]

Synthesis

Preparation methods

Strontium aluminate, primarily in the form of SrAl₂O₄, is synthesized through various laboratory and industrial methods to produce the base undoped compound, with techniques selected based on desired particle size, homogeneity, and scalability. The solid-state reaction remains the most traditional and widely adopted approach for bulk production. In this method, stoichiometric mixtures of strontium carbonate (SrCO₃) and aluminum oxide (Al₂O₃) are intimately ground and pelletized, then heated at temperatures between 1200°C and 1400°C for several hours in a reducing atmosphere, such as a mixture of hydrogen and nitrogen or carbon monoxide, to facilitate phase formation and prevent oxidation.^[37] This process yields crystalline SrAl₂O₄ with particle sizes typically in the micrometer range, though flux agents like boron oxide may be added to lower the reaction temperature and improve phase purity.^[38] The sol-gel method offers advantages in producing finer, more homogeneous powders at lower temperatures compared to solid-state synthesis. It involves the hydrolysis and condensation of metal alkoxides or salts, such as strontium acetate (Sr(CH₃COO)₂) or strontium nitrate (Sr(NO₃)₂) combined with aluminum isopropoxide (Al(OC₃H₇)₃), in the presence of solvents like water or ethanol and chelating agents such as citric acid to form a stable gel network.^[38] The gel is dried and calcined at approximately 1000°C for 2–4 hours under air or inert conditions, resulting in nanoscale SrAl₂O₄ particles with high surface area and uniform composition. This technique is particularly suited for laboratory-scale preparation where control over morphology is essential. Combustion synthesis provides a rapid, energy-efficient alternative for quick production of fine powders. In this process, aqueous solutions of strontium nitrate (Sr(NO₃)₂) and aluminum nitrate (Al(NO₃)₃) are mixed with organic fuels like urea or glycine, which act as reductants and complexing agents to ensure atomic-level mixing.^[39] Upon ignition, the mixture undergoes a self-propagating exothermic reaction reaching temperatures of 1500–2000°C in seconds, producing a foamy ash that is post-annealed at 800–1000°C to crystallize the SrAl₂O₄ phase.^[39] Fuel mixtures, such as urea and glycine, enhance phase purity by optimizing the adiabatic flame temperature and gas evolution.^[39] Across these methods, yield optimization involves precise stoichiometric control, minimization of secondary phases through atmosphere regulation, and post-synthesis purification steps like washing or sieving, achieving yields above 90% under controlled conditions.^[38] For optical-grade applications, such as phosphors, purity levels exceeding 99% are required, necessitating high-purity precursors (>99.9%) and avoidance of impurities that could quench luminescence, with dopant addition typically incorporated during the initial mixing for enhanced properties.^[40]

Doping processes

Doping in strontium aluminate, particularly SrAl₂O₄, involves the strategic incorporation of rare-earth ions to enable persistent luminescence by creating luminescent centers and trap states. The primary activator, Eu²⁺, is introduced through substitutional doping at Sr²⁺ lattice sites, facilitated by their comparable ionic radii (Eu²⁺: 1.20 Å; Sr²⁺: 1.18 Å), which minimizes structural distortion. Typical concentrations range from 0.5 to 2 mol%, as higher levels lead to concentration quenching that reduces emission efficiency.^[41]^[42]^[43] As a co-dopant, Dy³⁺ enhances the afterglow duration by generating deeper trap levels that store charge carriers, with optimal concentrations of 1-5 mol% depending on the synthesis conditions; for instance, 1 mol% Dy³⁺ paired with 1 mol% Eu²⁺ yields afterglow exceeding 10 hours. Dy³⁺ incorporation, despite its smaller ionic radius (0.91 Å), creates charge-compensating defects such as strontium vacancies, which deepen electron or hole traps near the valence or conduction bands, thereby prolonging the release of carriers to the Eu²⁺ centers.^[44]^[43]^[45] Other dopants, such as Nd³⁺ or Ce³⁺, are employed for spectral tuning while maintaining persistent properties. Nd³⁺ co-doping adjusts afterglow characteristics without significantly shifting the primary green emission from Eu²⁺, enabling applications requiring varied decay times. Ce³⁺, at low concentrations like 0.5 mol%, introduces blue emission bands around 480 nm, allowing tunable color outputs through energy transfer interactions with Eu²⁺. These dopants are integrated via methods such as co-precipitation, where precursors are mixed in solution to ensure homogeneous distribution, or high-energy milling, which refines particle size and incorporates ions during mechanical activation under reducing atmospheres.^[44]^[46]^[47]^[48] A key aspect of the doping mechanism involves defect formation for charge trapping, exemplified by hole capture at Eu²⁺ sites:

\text{Eu}^{2+} + h^+ \rightarrow \text{Eu}^{3+}

This process temporarily oxidizes Eu²⁺ to Eu³⁺, storing energy that is later released to sustain luminescence, with Dy³⁺ aiding in trap stabilization.^[44]

Properties

Physical and chemical properties

Strontium aluminate, with the chemical formula SrAl₂O₄, appears as a pale yellow to white microcrystalline powder that is odorless and non-flammable.^[16]^[49] This form is typical for the undoped compound, though color variations may occur with doping. The material is generally stable under ambient conditions but requires dry storage to prevent gradual hydrolysis.^[50] The density of SrAl₂O₄ is 3.559 g/cm³, reflecting its compact monoclinic crystal structure.^[2] It demonstrates high thermal stability, suitable for high-temperature ceramic applications.^[51] Hygroscopic behavior is minimal in sealed environments, though exposure to moisture can lead to slow surface reactions over time.^[52] SrAl₂O₄ is insoluble in water, where it instead undergoes hydrolysis to form strontium hydroxide and aluminum hydroxide.^[53]^[50] It remains chemically stable in neutral aqueous environments but reacts with strong acids or bases, releasing strontium and aluminum ions.^[54] This reactivity profile supports its use in durable, non-reactive applications while highlighting the need for controlled handling. The material has an approximate Mohs hardness of 4–5, aiding its incorporation into abrasives and coatings.^[55]

Optical and luminescent properties

Strontium aluminate (SrAl₂O₄) doped with Eu²⁺ exhibits efficient photoluminescence due to the allowed 4f–5d electronic transition in the europium ions, which enables broad-band excitation and visible emission. The excitation spectrum spans a wide range from 250 to 450 nm in the ultraviolet to visible region, with a prominent peak at approximately 380 nm, allowing the material to be activated by common light sources such as UV lamps or even daylight. This broad excitation profile arises from the crystal field splitting of the 5d orbitals in the SrAl₂O₄ host lattice, facilitating energy absorption and transfer to the luminescent centers.^[56] The emission spectrum of Eu²⁺-doped SrAl₂O₄ features a broad blue-green band centered at 520 nm, corresponding to the relaxation from the excited 4f⁶5d¹ to the ground 4f⁷ configuration of Eu²⁺. Co-doping with Dy³⁺ significantly enhances the persistence of this emission, resulting in an afterglow duration exceeding 12 hours, far surpassing traditional phosphors. The luminescent mechanism involves initial excitation of Eu²⁺ ions, followed by electron capture in shallow traps associated with Dy³⁺ ions (forming transient Dy⁴⁺ or related defects); these trapped electrons are then thermally released at room temperature, tunneling back to Eu²⁺ centers to sustain emission over extended periods. The role of Dy³⁺ dopants is primarily to create suitable trap depths (typically 0.6–0.8 eV) for thermal stimulation, as detailed in synthesis doping processes.^[56] This persistent luminescence is characterized by high internal quantum efficiency, often exceeding 70% under optimal excitation conditions, reflecting the material's superior energy conversion from absorbed photons to emitted light. The afterglow decay follows a non-exponential profile well-approximated by the empirical equation

I(t) = I_0 \left(1 + \frac{t}{\tau}\right)^{-1},

where I(t) is the intensity at time t, I_0 is the initial intensity, and \tau \approx 3600 s represents the characteristic persistence time, capturing the transition from rapid initial decay to a slow hyperbolic tail dominated by trap detrapping. This model highlights the material's ability to maintain visible luminosity (down to 0.32 mcd/m²) for over 10 hours post-excitation.^[56]

Applications

Industrial uses

Strontium aluminate, particularly when doped with rare-earth elements like europium and dysprosium, is integrated into photoluminescent paints for road markings and safety signage to provide extended visibility in low-light conditions. These paints absorb ambient light during the day and emit a green glow for over 10 hours after excitation, enhancing nighttime road safety by delineating lanes, edges, and hazards without relying on external power sources.^[57] Research has focused on durable formulations, such as silica-coated variants, to resist hydrolysis and weathering, ensuring longevity in outdoor environments.^[58] In infrastructure projects, these materials have been tested in glowing road strips and markings, contributing to sustainable traffic management by reducing energy use for lighting.^[59] In anticorrosion coatings for marine and aerospace applications, strontium aluminate serves as an additive to enhance protective properties, often combined with superhydrophobic layers to repel water and inhibit degradation. Doped strontium aluminate particles in epoxy or acrylic matrices provide both luminescent functionality and improved barrier effects against chloride ingress and oxidation, critical for metallic substrates exposed to harsh conditions like saltwater or high-altitude humidity.^[60] Studies demonstrate that silica-coated rare-earth-doped variants achieve superior anticorrosive performance, with impedance values exceeding 10^8 Ω cm^2 after prolonged salt spray exposure, outperforming traditional non-luminescent coatings.^[61] These additives are particularly valued in aerospace for their lightweight contribution and in marine settings for fouling resistance, where the material's chemical stability prevents leaching under thermal cycling.^[62] Mechanoluminescent sensors incorporating strontium aluminate enable real-time stress detection in composite materials, an emerging application since the 2010s driven by its ability to emit light under mechanical deformation. When embedded in polymers or epoxies, doped SrAl₂O₄ particles (e.g., Eu²⁺, Dy³⁺) produce visible mechanoluminescence upon applied force, allowing non-destructive monitoring of structural integrity in load-bearing components like aircraft panels or bridges.^[63] Sensitivity improvements through particle size optimization and matrix design have achieved detection thresholds as low as 0.1 MPa, facilitating early crack identification without invasive techniques.^[64] This technology supports predictive maintenance in industrial settings by visualizing stress distributions, with prototypes demonstrating recoverable emission after fatigue cycles.^[65] Strontium aluminate is also incorporated into composites for textiles and light-emitting diodes (LEDs), as well as biological imaging, due to its biocompatibility and tunable emission properties.^[6] Ongoing research explores its use in radiation dosimetry and waste immobilization, leveraging the material's stability and luminescent characteristics for detecting radiation exposure and encapsulating hazardous waste.^[7] As of 2024, it has been applied as a sacrificial layer in fabricating freestanding oxide membranes for advanced materials processing.^[66]

Commercial products

Strontium aluminate-based phosphorescent pigments are widely incorporated into glow-in-the-dark paints and stickers, enabling applications in consumer toys, novelty items, and safety signage such as emergency exit markers. These products absorb ambient light during the day and emit a visible glow for extended periods, typically 10-12 hours, providing reliable visibility without electricity. For instance, non-toxic formulations are used in children's toys and decorative novelties to create engaging luminescent effects, while in emergency contexts, they mark evacuation paths in buildings, enhancing safety during power outages.^[67]^[51] In the horology industry, Super-LumiNova, a proprietary strontium aluminate pigment developed by RC Tritec, is applied to watch and instrument dials for superior low-light readability. This material, doped with europium and dysprosium, charges rapidly under natural or artificial light and maintains luminescence for up to 15 hours, with the pigment's stability ensuring legibility for over 10 years under normal use. It has become the standard for high-end Swiss watches, outperforming older luminescent compounds in brightness and longevity.^[68]^[69] Photochromic inks derived from strontium aluminate nanoparticles have emerged as advanced security features in anticounterfeiting measures for currency and identification documents since 2020. These inks exhibit reversible color changes under UV or visible light exposure, combined with persistent luminescence, allowing for dynamic, multi-level authentication that is difficult to replicate. Developed through hybrid formulations with resins, they enable screen-printable patterns visible only under specific stimuli, enhancing document security against forgery.^[70] For road safety, strontium aluminate is integrated into reflective tapes and pathway markers that provide afterglow illumination exceeding 8 hours after light charging. These materials improve nighttime visibility for pedestrians and drivers by outlining lanes, curbs, and hazards, reducing accident risks in low-light conditions. Research highlights their use in photoluminescent road markings, where the pigments ensure sustained brightness without ongoing energy input, promoting sustainable infrastructure solutions.^[57]

Safety and environmental considerations

Health and toxicity

Strontium aluminate is generally classified as non-toxic for human health, with an acute oral LD50 exceeding 2000 mg/kg in rats and no observed acute dermal toxicity at similar doses.^[71] No significant adverse effects from ingestion or skin contact have been reported in available toxicological assessments, supporting its use in consumer products without inherent acute hazards.^[72] Inhalation of strontium aluminate dust may irritate the respiratory tract, particularly in poorly ventilated environments, though prolonged exposure data are limited.^[73] It is not classified as a carcinogen by the International Agency for Research on Cancer (IARC), with no evidence of genotoxicity or reproductive toxicity.^[73] In the environment, strontium aluminate is poorly water-soluble and does not meet the persistent, bioaccumulative, and toxic (PBT) or very persistent and very bioaccumulative (vPvB) criteria under REACH Annex XIII.^[74] However, as an inorganic compound, it is considered persistent and non-biodegradable in some assessments, with potential long-term hazards to aquatic environments.^[75]^[74] Certain safety data sheets classify it as acutely and chronically hazardous to aquatic life (e.g., Aquatic Chronic 2), with reported values including LC50 (96 h) of 6.8 mg/L for fish (Oncorhynchus mykiss) and EC50 (48 h) of 13 mg/L for invertebrates (Daphnia magna).^[75]^[76] Releases to the environment should be avoided. Compared to historical radium-based phosphors, strontium aluminate is safer as a non-radioactive alternative, eliminating risks of ionizing radiation exposure.^[77]

Handling and regulations

Strontium aluminate should be handled with appropriate personal protective equipment (PPE) to minimize dust exposure, including N95 masks or equivalent respirators, gloves, and protective eyewear, particularly during pouring or processing activities that may generate airborne particles.^[75] Although the material is non-flammable and non-combustible, it is advisable to avoid ignition sources and static electricity buildup when handling fine powders to prevent any potential dust-related hazards.^[76]^[78] For storage, strontium aluminate must be kept in tightly sealed containers in a cool, dry, well-ventilated area to protect it from moisture absorption, which could affect its luminescent properties.^[79]^[80] Under these conditions, the material exhibits a long shelf life exceeding 15 years without significant degradation.^[81] In terms of regulations, strontium aluminate is compliant with the European Union's REACH Regulation (EC) No. 1907/2006, as it does not contain substances of very high concern (SVHC) above threshold levels and is not subject to authorization or restriction under Annex XIV or XVII.^[82]^[76] In the United States, it is listed as an active substance on the Toxic Substances Control Act (TSCA) inventory, with no significant new use rules applying to standard forms.^[79]^[80] The compound faces no restrictions under the RoHS Directive for electrical and electronic equipment, as it does not involve prohibited heavy metals or flame retardants in relevant concentrations.^[83] Disposal of strontium aluminate is classified as non-hazardous waste under standard environmental regulations, allowing it to be managed through general industrial waste streams in accordance with local authority requirements.^[79]^[73] Where doped variants are involved, efforts to recycle valuable components such as rare earth elements are recommended to promote resource efficiency, though the base material itself poses no special disposal hazards.^[84]

References

[1]
CID 56846077 | Al2O4Sr - PubChem
CID 56846077 ; Molecular Formula. Al2O4Sr ; Synonyms. MFCD00054054; Strontium aluminate, -100 mesh, 99.5% trace metals basis ; Molecular Weight. 205.58 g/mol.
[2]
STRONTIUM ALUMINATE | 12004-37-4 - ChemicalBook
Aug 19, 2025 · Chemical Name: STRONTIUM ALUMINATE ; CBNumber: CB2159021 ; Molecular Formula: Al2O4Sr ; Molecular Weight: 205.58 ; MDL Number: MFCD00054054.<|control11|><|separator|>
[3]
Novel method of phosphorescent strontium aluminate coating ...
Dec 15, 2018 · Strontium aluminates are the most popular modern phosphorescent materials exhibiting long afterglow at room temperature and a broad spectral ...
[4]
Smart Mechanoluminescent Phosphors: A Review of Strontium ...
This paper presents a systematic and comprehensive review of strontium‐aluminate‐based luminescent materials' mechanoluminescence phenomena, mechanisms, ...
[5]
Original Synthetic Route To Obtain a SrAl2O4 Phosphor by the ...
SrAl2O4:Eu2+, Dy3+ has been extensively studied for industrial applications in the luminescent materials field, because of its excellent persistent ...<|control11|><|separator|>
[6]
Strontium Aluminate-Based Long Afterglow PP Composites - NIH
Apr 22, 2021 · The study evaluates strontium aluminate-based materials mixed with PP for long afterglow. It shows improved impact strength, but reduced ...
[7]
Evaluation of SrAl2O4:Eu, Dy phosphor for potential applications in ...
May 5, 2021 · The linear dose response demonstrates that SrAl 2 O 4 :Eu, Dy is a potential TLD dosimeter for both electron beams and photon beams at different beam energies.
[8]
Strontium aluminate | Al2O4Sr - ChemSpider
Strontium aluminate ; Molecular formula: Al2O4Sr ; Average mass: 205.580 ; Monoisotopic mass: 205.848348 ; ChemSpider ID: 10638005 ...Missing: composition | Show results with:composition
[9]
Aluminum strontium oxide (Al2SrO4) - PubChem - NIH
Strontium aluminate is a chemical compound of strontium and aluminum. When activated with a suitable dopant, it acts as a photoluminescent phosphor.
[10]
Effect of composition on the luminescent properties of Sr 4 Al 14 O 25
In recent years, the strontium aluminates hosts, for example SrAl2O4: Eu2+, Dy3+ and Sr4Al14O25: Eu2+, Dy3+ have attracted the researches intensely [1], since ...
[11]
SrAl2O4 (Strontium aluminate) molar mass
Molar Mass, Molecular Weight and Elemental Composition Calculator ; Strontium, Sr, 87.62 ; Aluminum, Al, 26.9815386 ; Oxygen, O · 15.9994 ...
[12]
SrAl2O4 Molar Mass - ChemicalAid
Composition of SrAl2O ; Strontium 87.62g ; Oxygen 63.9976g ; Aluminium/Aluminum 53.9631g ...
[13]
Strontium Aluminate, Sr4Al14O25 | AMERICAN ELEMENTS ®
American Elements offers Strontium aluminate (Tetradecaaluminum tetrastrontium pentacosaoxide, Sr4Al14O25) in both doped and undoped forms for phosphor ...Missing: variants | Show results with:variants
[14]
https://www.americanelements.com/strontium-aluminate-sr4al14o25-76125-60-5
[15]
Properties of SrAl2O4
Strontium aluminate phosphors dominate the persistent luminescence market with applications in emergency signage, watch dials, instrument panels, and safety ...
[16]
Green Afterglow of Undoped SrAl2O4 - PMC - NIH
Sep 9, 2021 · Taken from the Inorganic Crystal Structure Database (ICSD), the lattice parameters of monoclinic SrAl2O4 (a = 0.8447 nm, b = 0.8816 nm, c = 0. ...
[17]
mp-3094: SrAl2O4 (monoclinic, P2_1, 4) - Materials Project
SrAl2O4 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, ...Missing: undoped | Show results with:undoped
[18]
[PDF] Crystal structure, photoluminescence and cathodoluminescence of ...
Apr 11, 2019 · SrAl2O4 has a monoclinic crystal structure at ambient temperature and pressure [15], the hexagonal structure is the stable phase at a ...
[19]
Crystal structure of hexagonal SrAl2O4 at 1073K - ResearchGate
Aug 6, 2025 · The structure was hexagonal (space group P6{sub 3}, Z=6) with a=0.89260(3)nm, c=0.84985(2)nm and V=0.58639(3)nm{sup 3}. Final reliability ...
[20]
Energy transfer mechanism of Sr4Al14O25:Eu2+ phosphor
Sr4Al14O25 crystallizes as an orthorhombic structure with a space group of Pmma (51) and lattice constants of a = 24.7850 Å, b = 8.4870 Å, c = 4.8860 Å, a/b = ...
[21]
Unveiling the role of the hexagonal polymorph on SrAl2O4-based ...
It is well known that strontium aluminate, SrAl2O4, has two crystallographic polymorphs. Monoclinic symmetry, Mc, with space group P21 (a ¼ 8.447 Å, b ¼ ...
[22]
Role of Dopant on Long-Lasting Phosphor of Strontium Aluminate
Aug 6, 2025 · A hole trap is presumed to be ascribed to Sr defects, which increases and is stabilized by a charge compensation behavior upon doping Dy ion. ...
[23]
Defect structure and its relevance to photoluminescence in SrAl2O4 ...
Aug 5, 2025 · Rare-earth-doped strontium aluminates find many applications. One particular property is persistent phosphorescence. SrAl2O4:Eu2 +, Dy3 + and ...
[24]
Strontium - Element information, properties and uses | Periodic Table
Modern 'glow-in-the-dark' paints and plastics contain strontium aluminate. They absorb light during the day and release it slowly for hours afterwards.<|separator|>
[25]
[PDF] Strontium Aluminate Solid Solutions
Tristrontium aluminate hexahydrate, 3SrO.AI,Oa·6H20, was prepared hydrothermally as well as by various methods employing ordinary temperatures and ...Missing: elemental | Show results with:elemental
[26]
Phosphorescent Pigments | Nemoto & Co., Ltd. - 根本特殊化学
LumiNova is a series of Long afterglow pigments invented by Nemoto & Co., Ltd. in 1993. It provides 10 times brighter, 10 times longer afterglow against ...Missing: strontium persistent
[27]
Phosphorescent phosphor - US5424006A - Google Patents
Long persistent phosphors and persistent energy transfer technique ... synthetic method of europium doped strontium aluminate base light-storing material.
[28]
A New Long Phosphorescent Phosphor with High Brightness, SrAl2 ...
A New Long Phosphorescent Phosphor with High Brightness, SrAl2 O 4 : Eu2 + , Dy3 +. T. Matsuzawa, Y. Aoki, N. Takeuchi and Y. Murayama. © 1996 ECS - The ...Missing: paper | Show results with:paper
[29]
Strontium Aluminate/Polymer Composites - ResearchGate
... hexagonal polymorph phase of these films with orthorhombic Sr4Al14O25 as secondary phase. The incorporation of Tm³⁺ ions in strontium aluminate host lattice ...
[30]
Super-LumiNova Watches - Chrono24 Magazine
Sep 1, 2025 · Super-LumiNova is a non-radioactive, re-chargeable luminous material with strong luminosity, lasting about 15 hours, and is a Swiss afterglow ...
[31]
https://www.chrono24.com/magazine/super-luminova-watches-luminous-timepieces-from-radium-to-tritium-p_163991/
[32]
https://www.bobswatches.com/rolex-blog/rolex-info/evolution-rolex-luminous.html
[33]
https://www.databridgemarketresearch.com/reports/global-strontium-aluminate-market
[34]
Smart Mechanoluminescent Phosphors: A Review of Strontium ...
Nov 13, 2022 · This paper presents a systematic and comprehensive review of strontium-aluminate-based luminescent materials' mechanoluminescence phenomena, ...
[35]
[PDF] Laser Synthesis and Luminescence Properties of SrAl2O4:Eu , Dy ...
The microstructure and elemental composition of the phosphors were characterized by scanning electron microscopy (SEM JEOL JSM-6400 microscope) with energy.
[36]
Advanced Techniques for Preparation of Strontium Aluminate Phases
The solid state synthesis described in Chapter 4.3 is the traditional way for the synthesis of strontium aluminate phase. Small amounts of fluxing agents (Fig.1) ...
[37]
Solution combustion synthesis of strontium aluminate, SrAl 2 O 4 ...
The fuel-mixture approach (urea and glycine) clearly represented a better option, since (α,β)-SrAl2O4 resulted directly from the combustion reaction. The ...
[38]
Strontium Aluminate Doped with Europium, SrAl 2 O 4 with 3 wt% Eu
Rating 5.0 (1) Properties ; Molar mass, ~185.27 g/mol ; Density, ~3.8–4.2 g/cm³ ; Melting Point, ~1600–1650°C ; Shape and Appearance, Solid, Thin film, Disc, or rectangular.Missing: SrAl2O4 | Show results with:SrAl2O4<|control11|><|separator|>
[39]
Eu2+ luminescence in strontium aluminates - RSC Publishing
Eu2+ emission in strontium aluminates varies from UV to red, related to crystal-field splitting and oxygen interaction. Emission shifts with Sr/Al ratio, and ...
[40]
[PDF] Eu2+ luminescence in strontium aluminates - UU Research Portal
Eu2+ ions substitute for Sr2+ ions because of the similar atomic radius and the same charge. The 12-fold coordinated. Sr site in the magnetoplumbite structure ...
[41]
Synthesis and cytotoxic effects of SrAl 2 O 4 persistent luminescence ...
Apr 4, 2016 · ... dopants (SAO). Strontium aluminate co-doped with 1% Eu2+ and 1% Dy3+ (SAO11), and with 1% Eu2+ and 3% Dy3+ (SAO13) have very good persistent ...<|separator|>
[42]
None
### Summary of Doping Processes for SrAl₂O₄:Eu,Dy (Persistent Luminescence)
[43]
Visualization of trap distribution in SrAl2O4:Eu2+,Dy3+ revealed by ...
Jun 24, 2025 · The co- dopant Dy3+ plays the role of a better electron trap, which contributes to the longer PersL compared to oxygen vacancies or defects ...
[44]
Tunable luminescence and electrical properties of cerium doped ...
They can be widely used for lighting applications in the automobile and electronic industries [1]. Among the various rare earth aluminate phosphor material, ...
[45]
Preparation and properties of Eu and Dy co-doped strontium ...
The long afterglow nanomaterials of strontium aluminate co-doped by Eu and Dy have been synthesized by co-precipitation combined hydrothermal method.Missing: typical | Show results with:typical
[46]
co-doped strontium aluminate phosphor by soft mechanochemistry ...
SrAl2O4: Eu2+, Dy3+ powder as a ML phosphor was synthesized via soft mechanochemical pretreatment in a high-energy density stirred media mill and subsequent ...
[47]
Strontium Aluminate (SrAl2O4)-Sputtering Target - FUNCMATER
Rating 5.0 (67) ... mass：205.58 g/mol. Appearance：Pale yellow powder. Density：3.559 g/cm3. Crystal structure：Monoclinic. Application. When activated with a suitable dopant (e.g. ...
[48]
Persistent Luminescence Strontium Aluminate Nanoparticles ... - NIH
Sep 23, 2014 · Strontium aluminate readily hydrolyzes in water to form nonluminescent aluminum hydroxide precipitate and soluble strontium hydroxide.<|separator|>
[49]
SR3088 Strontium Aluminate Powder (CAS: 12004-37-4)
Starting from $100.00 In stockMay 13, 2025 · Strontium Aluminate Powder Specifications ; CAS Number. 12004-37-4 ; Chemical Formula. Al2O4Sr ; Particle Size. 10-30 μm, 30-50 μm, or customized.
[50]
[PDF] synthesis and characterization of phosphorescent
In order to produce the crystalline strontium aluminate compound, the precursor is heated to temperatures between 700-. 1000˚C in an oxidizing environment.
[51]
Strontium Aluminate | AMERICAN ELEMENTS ®
The number of electrons in each of Strontium's shells is [2, 8, 18, 8, 2] and its electron configuration is [Kr] 5s2. The strontium atom has a radius of 215 pm ...
[52]
None
### Physical and Chemical Properties Summary
[53]
https://www.americanelements.com/strontium-aluminate-12004-37-4
[54]
Aluminate Long Afterglow Luminescent Materials in Road Marking ...
This paper reviews the research progress and development of aluminate long afterglow luminescent materials in the field of road marking
[55]
Eu 2+ , Dy 3+ coatings for durable luminescent road markings
However, strontium aluminate (SA) (SrAl2O4:Eu2+, Dy3+), commonly used in self-illuminating markings, is prone to hydrolysis when exposed to moisture, ...
[56]
Glowing roads take a rain check | News - Chemistry World
May 7, 2014 · The road strips glow thanks to strontium aluminate crystals doped with europium. The collaboration aims to make roads sustainable and ...
[57]
Development of silica-coated rare-earth doped strontium aluminate ...
Development of silica-coated rare-earth doped strontium aluminate toward superhydrophobic, anti-corrosive and long-persistent photoluminescent epoxy coating.
[58]
Long afterglow luminescent superhydrophobic coating for metal ...
Sep 15, 2025 · ... corrosion protection performance of the coatings can be further enhanced. ... The incorporation of micron-sized strontium aluminate ...
[59]
Preparation of photoluminescent and anticorrosive epoxy paints ...
Apr 13, 2022 · The produced paints displayed high durability and photostability. Keywords: Anticorrosion; Epoxy; Luminescence; Strontium aluminate; Sugarcane ...
[60]
Smart Mechanoluminescent Phosphors: A Review of Strontium ...
Nov 13, 2022 · Mechanoluminescent sensors based on SAOE or SAOED can monitor the stress distribution on a solid surface in real time, detect sudden damage ( ...
[61]
Improving the Sensitivity of the Mechanoluminescence Composite ...
Jun 23, 2022 · Mechanoluminescence (ML) technologies have been proposed for detecting cracks and evaluating the stress/strain states in their vicinity. ML ...
[62]
Recovering mechanoluminescence in SAOED/epoxy stress sensors ...
Mar 6, 2025 · Specifically, strontium aluminate phosphors have been broadly investigated due to their high and long-lasting light emission and fast response ...
[63]
Structure and mechanical properties of ceramic materials based on ...
Feb 1, 2021 · In this study, the effect of a small amount of strontium hexaaluminate (3 wt %) additives on the properties of alumina- and zirconia-based ceramics is ...Missing: aluminate durability
[64]
Applications of Strontium Aluminate Cements - IntechOpen
Jul 2, 2014 · Such castables have valuable properties, including low thermal expansion coefficient, good thermal conductivity, good thermal shock resistance, ...Missing: durability | Show results with:durability
[65]
Electrical properties and thermal expansion of strontium aluminates
Such additions of strontium aluminate phase were found to improve thermomechanical properties and the stability of the membrane materials under operation ...
[66]
A Brighter Choice for Safety - NASA Spinoff
LUNAplast, which benefited from tests conducted at Johnson Space Center, is so successful that NASA engineers selected it for the emergency exit pathway ...
[67]
In-Depth: Luminous Dials, What Makes Them Glow, And ... - Hodinkee
Jul 5, 2018 · Strontium aluminate seems to be a highly stable phosphor, and Super-LumiNova dials, at least thus far, appear to not suffer from the gradual ...<|separator|>
[68]
Home | rctritec
SUPERLUMINOVA LOGO. Menu Menu. Projekt initialisiert. Um nun die Site zu ... RC Tritec AG; Speicherstrasse 60A; 9053 Teufen; Schweiz; +41 71 335 73 73 · sales ...
[69]
ACS Omega - ACS Publications - American Chemical Society
Oct 7, 2021 · Photochromic and fluorescent ink using photoluminescent strontium aluminate pigment and screen printing towards anticounterfeiting documents.
[70]
[PDF] Safety Data Sheet
Oct 20, 2021 · Exposure route. Method. 201426-52-0 Strontium aluminate doped with europium and dysprosium. LD50. >2000 mg/kg oral. LD50. >2000 mg/kg dermal.
[71]
[PDF] Toxicology Report No. S.0032635-15, June 2019 - DTIC
Jun 7, 2019 · The oral LD50 in rats is reported to be >10,000 mg/kg (HSDB 2012a). No chronic exposure data were found. 7.7.2.2 Inhalation. Inhalation studies ...
[72]
[PDF] SAFETY DATA SHEET - Materion
May 21, 2015 · Information on likely routes of exposure. Inhalation. Prolonged inhalation may be harmful. Skin contact. No adverse effects due to skin contact ...
[73]
[PDF] Safety Data Sheet - lumentics
Oct 11, 2016 · Europium / dysprosium doped strontium aluminate. 1.1. Product ... LD50: Lethal dose, 50 percent. NOAEL: No observed adverse effect level.
[74]
BfS - Radioactive materials in watches - Bundesamt für Strahlenschutz
Jan 22, 2024 · Nowadays, there are very good luminous, non-radioactive paints available, which are manufactured on the basis of e.g. Strontium Aluminate ( ...<|separator|>
[75]
[PDF] EverGlow TL300 Photoluminescent Pigment_SDS_11Mar2018
Mar 11, 2018 · (STRONTIUM ALUMINATE), CLASS 9, PGIII, MARINE POLLUTANT LABEL. DUE TO ITS AQUATIC TOXICITY UNDER THE UN/GHS CLASSICIFICATION SYSTEM. IN THE ...
[76]
[PDF] Strontium aluminate - SAFETY DATA SHEET
Nov 18, 2022 · Water Solubility. Insoluble in water. Solubility in other solvents. No information available. Partition Coefficient (n-octanol/water).
[77]
[PDF] Material Safety Data Sheet
Mar 21, 2017 · Potential Health Effects: Eyes: May cause irritation. Skin: May cause irritation. Ingestion: N/A. Inhalation: N/A. Chronic: N/A. Signs & ...
[78]
https://glasscolor.com/media/wysiwyg/Glow_Powder_MATERIAL_SAFETY_DATA_SHEET.pdf
[79]
[PDF] SAFETY DATA SHEET - Fisher Scientific
Mar 30, 2024 · Melting Point/Range. No data available. Boiling Point/Range. No information available. Flash Point. No information available. Evaporation Rate.
[80]
https://www.fishersci.com/store/msds?partNumber=AA39647&productDescription=keyword&vendorId=VN00024248&countryCode=US&language=en
[81]
Is Strontium Aluminate Based Glow Powder Safe and Non Toxic?
Sep 25, 2022 · If you are still doubting, our strontium aluminate based glow in the dark powder are certificated by REACH, and passed the testing standard of ...
[82]
restricted-subs-referred-art-4-rohs - ECHA
The Support section provides tools and practical guidance to companies which have responsibilities under the EU chemicals legislation. REACH. Guidance on REACH ...Missing: aluminate | Show results with:aluminate
[83]
[PDF] CORE Glow Powder MATERIAL SAFETY DATA SHEET (MSDS ...
SECTION X - HANDLING & STORAGE INFORMATION Store closed in cool dry area when handling wear protective clothing and respiratory protection. Avoid scattering ...<|separator|>