Molybdenum Silicide (MoSi2)-Powder

Characteristic

Molybdenum disilicide (MoSi₂, or molybdenum silicide), an intermetallic compound, a silicide of molybdenum, is a refractory ceramic with primary use in heating elements. It has moderate density, melting point 2030 °C, and is electrically conductive. At high temperatures it forms a passivation layer of silicon dioxide, protecting it from further oxidation. The thermal stability of MoSi₂ alongside its high emissivity make this material, alongside WSi₂ attractive for applications as a high emissivity coatings in heat shields for atmospheric entry. MoSi₂ is a gray metallic-looking material with tetragonal crystal structure (alpha-modification); its beta-modification is hexagonal and unstable.

Chemical formula：MoSi₂

Molar mass：152.11 g/mol

Appearance： gray metallic solid

Density：6.26 g/cm³

Melting point：2,030 °C (3,690 °F; 2,300 K)

Crystal structure：Tetragonal

Application

Molybdenum disilicide heating elements can be used for temperatures up to 1800 °C, in electric furnaces used in laboratory and production environment in production of glass, steel, electronics, ceramics, and in heat treatment of materials. While the elements are brittle, they can operate at high power without aging, and their electrical resistivity does not increase with operation time. Their maximum operating temperature has to be lowered in atmospheres with low oxygen content due to breakdown of the passivation layer.

Other ceramic materials used for heating elements are e.g. silicon carbide, barium titanate, and lead titanate composite materials.

Molybdenum disilicide is used in microelectronics as a contact material. It is often used as a shunt over polysilicon lines to increase their conductivity and increase signal speed.