Lanthanum tetraboride is a binary inorganic compound of lanthanum and boron with the chemical formula . The compound forms a gray to black crystalline solid and demonstrates metallic conductivity.
Properties Lanthanum tetraboride is a refractory, high-hardness inorganic compound crystallizing in the tetragonal crystal system, space group P4/mbm. The arrangement of atoms is the same as in the tetraborides of cerium, thorium and uranium (CeB4, ThB4, UB4) is distinct from the more common lanthanum hexaboride but shares high-temperature stability, with its boron sublattices containing structural elements of both diborides and hexaborides. The compound undergoes a series of phase transitions under high pressure.
Synthesis Lanthanum tetraboride can be prepared by the reduction of lanthanum oxide by boron carbide under vacuum:
Another method involves heating lanthanum metal and boron at 1300 °C under vacuum.
Uses The compound is generally a subject of materials science research. Also it is especially suitable for high-temperature applications.
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