Yttrium Borides - YB₅₀

YB₅₀

YB₅₀ crystals have orthorhombic structure with space group P2₁2₁2 (No. 18), a = 1.66251 nm, b = 1.76198 nm, c = 0.94797 nm. They can be grown by heating a compressed pellet of yttria (Y₂O₃) and boron powder to ~1700 0C. Above this temperature YB₅₀ decomposes into YB₁₂ and YB₆₆ without melting. This makes it difficult to grow a single crystal of YB₅₀ by the melt growth method. Rare earth elements from Tb to Lu can also crystallize in the M₅₀ form.