Scandium oxide, also known as scandium trioxide, is a white solid with a cubic structure of rare earth sesquioxide, a molecular structure of Sc2O3, a melting point of 2403 ℃± 20 ℃, insoluble in water and soluble in hot acid.
Scandium, a simple substance, is usually used in alloys, and scandium oxide also plays a crucial role in ceramic materials. For example, tetragonal zirconia ceramic materials, which can be used as electrode materials of solid oxide fuel cells, have a very unique characteristic. The conductivity of such electrolytes will increase with the increase of ambient temperature and oxygen concentration in the natural environment. However, the molecular structure of this kind of ceramic materials cannot exist stably by itself, and does not have industrial production value; It is necessary to add some materials that can determine this kind of structure to ensure the original characteristics.
In addition, silicon nitride, an engineering ceramic material with high strength and high temperature resistance, is used as a densifier and stabilizer. Scandium oxide, as a densifier, can form a refractory phase Sc2Si2O7 at the edge of fine particles, thereby reducing the high-temperature deformation of engineering ceramics. Compared with other oxides, Scandium oxide can better improve the high-temperature mechanical properties of silicon nitride. Adding a little Sc2O3 to UO2 in high temperature reactor fuel can prevent lattice changes, body size increase and cracks caused by conversion of UO2 to U3O8.
Scandium oxide is decomposed from scandium salt when it is heated. It can be used as the evaporation material of semiconductor material coating, as well as the wavelength adjustable solid laser, high-definition television electron gun, metal halide lamp, etc.
