Barium Boride (BaB6)-Powder

Characteristic

Calcium hexaboride (sometimes calcium boride) is a compound of calcium and boron with the chemical formula CaB₆. It is an important material due to its high electrical conductivity, hardness, chemical stability, and melting point. It is a black, lustrous, chemically inert powder with a low density. It has the cubic structure typical for metal hexaborides, with octahedral units of 6 boron atoms combined with calcium atoms. CaB6 and lanthanum-doped CaB₆ both show weak ferromagnetic properties, which is a remarkable fact because calcium and boron are neither magnetic, nor have inner 3d or 4f electronic shells, which are usually required for ferromagnetism.

Chemical formula：CaB₆

Molar mass：104.94 g/mol

Appearance：black powder

Density：2.45 g/cm³

Melting point：2,235 °C (4,055 °F; 2,508 K)

Solubility in water：insoluble

Crystal structure：Cubic

Application

Calcium hexaboride is used in the manufacturing of boron-alloyed steel and as a deoxidation agent in production of oxygen-free copper. The latter results in higher conductivity than conventionally phosphorus-deoxidized copper owing to the low solubility of boron in copper. CaB6 can also serve as a high temperature material, surface protection, abrasives, tools, and wear resistant material.

CaB₆ is highly conductive, has low work function, and thus can be used as a hot cathode material. When used at elevated temperature, calcium hexaboride will oxidize degrading its properties and shortening its usable lifespan.

CaB₆ is also a promising candidate for n-type thermoelectric materials, because its power factor is larger than or comparable to that of common thermoelectric materials Bi₂Te₃ and PbTe.

CaB also can be used as an antioxidant in carbon bonded refractories.