Single-crystal growth and properties of CrB, Cr 3B 4, Cr 2B 3 and CrB 2 from high-temperature aluminum solutions

Single crystals of CrB, Cr ₃B ₄, Cr ₂B ₃, and CrB ₂ were grown from high-temperature Al solutions. The crystals were examined by X-ray diffraction and chemical analysis. The CrB, Cr ₃B ₄, and Cr ₂B ₃ single crystals were obtained as columnar and thick-platelet crystals having well-developed (010) and (100) faces with maximum dimensions of 3 to 8 mm. CrB ₂ single crystals 4-8 mm in size were obtained as thick platelets having well-developed (0001) planes or as needles elongated in the <0001> direction. The Vickers microhardness and electrical resistivity of the crystals were measured, and oxidation at high temperature in air was studied.