Crystallography of the Ru–B and Os–B Systems

Abstract

The Ru–B and Os–B systems were investigated by x‐ray powder diffraction. In addition to Aronsson's hexagonal Ru₇B₃ phase, two new hexagonal Ru–B phases were found: RuB₂(D_6h¹—P6/mmm, a₀=2.852 A, c₀=2.855 A) and Ru₂B₅(D_6h⁴—P6/mmc, a₀=2.89 A, c₀=12.81 A. In the Os–B system, two new hexagonal phases, isomorphous with the latter Ru–B phases, were found: OsB₂(a₀=2.876 A, c₀=2.871 A) and Os₂B₅ (a₀=2.91 A, c₀=12.91 A). RuB₂ and OsB₂ are isomorphous with MoB₂; Ru₂B₅ and Os₂B₅ are isomorphous with W₂B₅.