Bismuth oxide
Properties
Chemical formula: Bi₂O₃
Name: Bismuth oxide / bismuth(III) oxide
CAS No.: 1304-76-3
Molar mass: 465.96 g/mol
Density: 8.90 g/cm³
Melting point: approx. 817 °C
Boiling point: approx. 1890 °C
Color: yellow to pale yellow
Form: fine powder
Solubility: insoluble in water, soluble in inorganic acids
Bismuth oxide (Bi₂O₃) is an inorganic metal oxide supplied as a fine, odorless yellow to pale-yellow powder. The material has a high density of 8.90 g/cm³ and is used in a variety of ceramic, electronic and optical applications.
Bismuth oxide is insoluble in water and alcoholic media but dissolves in inorganic acids to form the corresponding bismuth(III) salts. The compound exists in several crystalline modifications, including the α, β, γ and δ phases.
The α phase is stable at room temperature and transforms at approximately 729 °C into the cubic δ phase. This high-temperature modification exhibits high oxygen-ion conductivity, making Bi₂O₃ relevant for functional ceramics, solid electrolytes and oxygen-sensing technologies.
An important processing characteristic of bismuth oxide is its fluxing behavior in ceramic and glass systems. It can help lower sintering temperatures and is therefore used in lead-free glazes, enamels and specialty glass compositions.
Bismuth oxide can also increase the refractive index of specialty optical glasses. Compared with oxides of certain toxic heavy metals, particularly lead-based compounds, Bi₂O₃ is used as an alternative component in various lead-free formulations.
Industrial production is mainly based on thermal oxidation of metallic bismuth or precipitation of bismuth compounds followed by calcination, for example from bismuth nitrate.
Bismuth and its compounds are particularly important in electronics, functional ceramics, glass technology, catalysis and oxygen-ion-conducting materials. Would you like to buy bismuth oxide? Auremo can provide information about available purity grades and delivery conditions. The bismuth price, bismuth metal price and bismuth price per kg primarily refer to metallic bismuth, while the bismuth oxide price depends on purity, quantity and material specifications.
Advantages
• Suitable for lead-free glazes and enamels
• Effective fluxing behavior in ceramic processing
• High oxygen-ion conductivity of the high-temperature δ phase
• Can reduce ceramic sintering temperatures
• High material density
• Suitable for functional oxide materials
• Increases the refractive index of specialty glasses
• Can replace lead-containing components in selected formulations
Applications
• Zinc oxide varistors
• Multilayer ceramic capacitors (MLCC)
• Solid oxide fuel cells (SOFC)
• Oxygen sensors
• Functional ceramics
• Glass manufacturing
• Lead-free glazes and enamels
• Specialty optical glasses
• Yellow pigment formulations
• Oxidation catalysts
• Pyrotechnic compositions
Auremo offers bismuth oxide and other specialty oxide materials for industrial, technical and research applications. If you have questions about purity, available quantities or delivery conditions, please contact us directly.
