Yttrium Oxide, Yttria Yttrium Sesquioxide, Yttrium Trioxide, 1314-36-9

Yttrium Oxide, Yttria Yttrium Sesquioxide, Yttrium Trioxide, 1314-36-9

Yttrium(III) oxide 

Yttrium(III) oxide (Y₂O₃), commonly called yttria, is a high-melting rare-earth oxide valued for thermal stability, chemical inertness, and optical performance. It is a key host lattice for phosphors and a building block for advanced ceramics, lasers, and electronic components.

Chemical identity and key properties

• Chemical name: Yttrium(III) oxide

• Formula: Y₂O₃

• Molar mass: 225.81 g/mol

• CAS number: 1314-36-9

• EC number: 215-233-5

• Appearance: White, fine powder

• Crystal structure: Cubic bixbyite

• Density: ~5.0 g/cm³ (bulk density depends on particle size)

• Melting point: ~2,425 °C

• Boiling point: ~4,300 °C

• pH (aqueous suspension): Slightly basic

• Thermal conductivity (polycrystalline): Low-to-moderate (application-dependent)

• Electrical behavior: Insulating ceramic

Solubility and reactivity

• Solubility: Insoluble in water and most organic solvents.

• Acids: Slowly reacts with strong acids to form yttrium salts; solubility improves with complexing agents.

• Bases: Generally stable; does not readily dissolve in alkali.

• Redox: Y₂O₃ is already in a highly stable oxidized state; non-reducible under mild conditions.

• Compatibility: Chemically compatible with alumina, zirconia, and many refractory oxides.

Production routes and material grades

• Ore sources: Typically derived from ionic clays and rare-earth ores (e.g., bastnäsite, monazite) after REE separation.

• Typical process: Acid leaching → REE solvent extraction → precipitation (hydroxide/carbonate) → calcination to Y₂O₃ → milling and classification.

• Alternative high-purity route: Precipitation from high-purity yttrium nitrate → calcination → controlled atmosphere sintering to minimize impurities.

Available grades and forms

• Technical grade: 99.9% (3N) for general ceramics and refractories.

• High purity: 99.99%–99.999% (4N–5N) for phosphors, optics, and electronic applications.

• Particle sizes: Nano (20–100 nm), sub-micron, micronized (D50 0.5–5 μm), agglomerate-controlled powders.

• Morphology: Spherical or irregular, depending on synthesis; surface area tailored (BET 5–50 m²/g).

Applications and mechanisms

Phosphors and display technologies

• Red phosphors: Eu³⁺-doped Y₂O₃ (Y₂O₃:Eu) is a standard red-emitting phosphor (≈611 nm emission) for LEDs and displays, chosen for high quantum efficiency and thermal stability.

• Other dopants: Tb³⁺ (green emission), Er³⁺/Tm³⁺ (IR/visible upconversion).

Optics and lasers

• Transparent ceramics: Sintered Y₂O₃ can be made optically transparent for IR windows and high-temperature viewports due to low scattering and high melting point.

• Laser hosts: YAG (Y₃Al₅O₁₂) and YSGG derive yttrium from Y₂O₃ precursors; dopants (Nd³⁺, Er³⁺, Yb³⁺) enable solid-state lasers.

Electronics and magnetics

• YIG (Y₃Fe₅O₁₂): Y₂O₃ precursor to yttrium iron garnet used in microwave components and magneto-optical devices.

• Dielectrics: High-resistivity ceramics for insulating layers and sensor substrates.

Advanced ceramics and thermal systems

• Zirconia stabilization: Y₂O₃-stabilized ZrO₂ (YSZ) provides high fracture toughness and oxygen-ion conductivity; widely used in thermal barrier coatings and SOFC electrolytes.

• Refractories: Additive to improve creep resistance and grain boundary stability.

Metallurgy and surface treatments

• Alloying and inclusions control: Minor yttrium additions (via Y₂O₃ or salts) refine grain boundaries and enhance oxidation resistance.

• Polishing: As a mild abrasive in specialized optical finishing where alumina or ceria may be too aggressive or chemically reactive.

Specification parameters for procurement

• Purity: 3N/4N/5N; specify total REE content and specific trace limits (Fe, Si, Ca, Al, Na, Cl, S, Pb).

• Particle size distribution: D10/D50/D90 or surface area (BET); agglomerate control; sieve residue.

• Loss on ignition (LOI): Indicates residual hydroxide/carbonate or adsorbed moisture.

• Moisture content: Karl Fischer or gravimetric; important for sintering predictability.

• Specific surface area (BET): Critical for sintering and phosphor dispersion.

• Phase purity: XRD-confirmed cubic Y₂O₃; absence of oxyhydroxides.

• Whiteness/L-value: For optical/phosphor consistency.

• Conductivity/ionic purity: For electronic applications (low ionic contaminants).

• Packaging cleanliness: Low ionic leachables, antistatic controls for nano-grade.

Handling, safety, and compliance

• Hazards: Low acute toxicity; fine powders can irritate eyes/respiratory tract.

• PPE: Gloves, safety glasses, FFP2/FFP3 dust mask for nano/submicron powders.

• Storage: Dry, sealed containers; avoid humidity to prevent surface hydroxylation.

• Waste: Manage as inert ceramic/rare-earth waste per local regulations.

• Transport identifiers: Typically non-flammable, non-reactive; check supplier SDS for specific UN classification.

• Documentation: SDS, TDS, CoA with batch-specific particle size, purity, and trace metals; REACH and RoHS statements if applicable.

Comparison to related oxides

• Versus ceria (CeO₂): Y₂O₃ is less chemically active (no Ce³⁺/Ce⁴⁺ redox cycling) but offers better high-temperature phase stability for transparent ceramics; ceria excels in oxygen storage and catalysis.

• Versus alumina (Al₂O₃): Alumina is cheaper and harder as an abrasive, but yttria has higher IR transparency potential and is preferred as a dopant/host in phosphors.

• Versus zirconia (ZrO₂): Y₂O₃ is the stabilizer; YSZ leverages yttria to achieve toughening and ionic conductivity for thermal barriers and fuel cells.

ERP-ready data block (concise)

• Product name: Yttrium(III) oxide (Y₂O₃)

• CAS: 1314-36-9

• EC: 215-233-5

• Purity grades: 99.9–99.999%

• Appearance: White powder, cubic phase

• Density: ~5.0 g/cm³

• Melting point: ~2,425 °C

• Solubility: Insoluble in water; limited acid solubility

• Forms: Nano, submicron, micronized

• Applications: Phosphors (Y₂O₃:Eu), transparent ceramics, YAG/YIG precursors, YSZ stabilizer, IR windows

🧾 Yttrium(III) Oxide (Y₂O₃) – Synonyms

Yttrium(III) Oxide is referred to in literature and commercial use by several alternative names. The most common ones include:

• Yttrium Oxide

• Yttrium(III) Oxide

• Yttria (widely used short name)

• Yttrium Sesquioxide

• Yttrium Trioxide

• Y₂O₃ (chemical formula notation)