Yttrium oxide
[CAS# 1314-36-9]

Identification

• Classification: Inorganic chemical industry >> Inorganic salt >> Oxides of rare earth metals, yttrium or scandium
• Name: Yttrium oxide
• Synonyms: Yttrium(III) oxide
• Molecular Formula: Y₂O₃
• Molecular Weight: 225.81
• CAS Registry Number: 1314-36-9
• EC Number: 215-233-5
• SMILES: [O-2].[O-2].[O-2].[Y+3].[Y+3]

Properties

• Density: 5.01 g/mL
• Melting point: 2410 °C
• Water solubility: insoluble

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335-H413
• Safety Statements: P261-P264-P264+P265-P271-P273-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413

Discovery and Applications

Yttrium, the source element of yttrium oxide, was first discovered in 1794 by Finnish chemist Johan Gadolin. Yttrium oxide was discovered shortly thereafter as chemists attempted to isolate and characterize yttrium compounds. Yttrium oxide was formally identified and isolated as a stable compound suitable for further study and application in various fields of technology.

Early methods of isolating yttrium oxide were by precipitation from yttrium salts dissolved in aqueous solution. By carefully controlling pH and temperature, researchers were able to precipitate yttrium hydroxide, which was then calcined to produce yttrium oxide. Yttrium oxide can also be obtained by thermal decomposition of yttrium compounds such as yttrium nitrate or yttrium chloride at high temperatures. This process heats the compound in a controlled environment to ensure the formation of pure yttrium oxide.

The chemical formula of yttrium oxide is Y₂O₃, and it crystallizes in a cubic fluorite structure. The melting point of primary yttrium oxide is approximately 2,410°C, making it suitable for high-temperature applications. It exhibits high optical transparency in the infrared spectrum, which is valuable in a variety of optical applications. Yttrium oxide is an excellent electrical insulator, making it very useful in the electronics and semiconductor industries.

Yttrium oxide is widely used in the production of phosphors for cathode ray tubes (CRTs) and fluorescent lamps. Yttrium oxide-based phosphors emit a variety of colors when excited by electrons, resulting in vivid colors and efficient lighting. Yttrium oxide is used as a dielectric material in thin film transistors (TFTs) and integrated circuits (ICs). Its high dielectric constant and electrical insulation properties facilitate miniaturization and performance improvements in electronic devices.

Yttrium oxide is used as a dopant in the production of ceramic capacitors because of its ability to enhance the dielectric properties of ceramic materials and its reliability. Ceramic capacitors are essential components in electronic circuits, providing energy storage and signal filtering. Yttrium oxide is added to ceramic materials to improve their mechanical strength, thermal stability, and chemical resistance. These advanced ceramics are used in aerospace, defense, and industrial applications.

Yttrium oxide is used as a support material for catalysts in various chemical processes. Its high surface area and thermal stability make it suitable for dispersing and stabilizing active catalytic species, thereby increasing reaction rates and selectivity. Yttrium oxide is used as an emission control catalyst in automotive catalytic converters. It helps to reduce harmful emissions such as nitrogen oxides (NOx), carbon monoxide (CO), and hydrocarbons (HC) in vehicle exhaust, thereby cleaning the air.

Yttrium oxide-based scintillation detectors are used in medical imaging devices such as positron emission tomography (PET) machines and gamma cameras. These detectors convert incident radiation into visible light photons, enabling precise imaging and diagnosis in healthcare applications. Yttrium oxide is incorporated into radiopaque markers used in medical procedures such as endoscopy and surgery. Radiopaque markers enhance visibility in X-ray imaging and help accurately locate medical devices in the body.

References

1965. Experimental comparison of dosimetric data for yttrium oxide (Y90) rods. The International Journal of Applied Radiation and Isotopes, 16(4).
DOI: 10.1016/0020-708x(65)90174-2

2024. Assessment of toxicity and oxidative stress induced by rare earth oxide nanoparticles in brine shrimp (Artemia salina). Chemosphere, 363.
DOI: 10.1016/j.chemosphere.2024.143683

1997. Effect of the substitution of Y2O3 for CaO on the bioactivity of 2.5CaO · 2SiO2 glass. Biomaterials, 18(5).
DOI: 10.1016/s0142-9612(96)00118-4