Polycrystalline samples of ScRh3Bx, which consists of reactive Sc and high melting point Rh and B elements, have been successfully synthesized by the arc melting method. ScRh3Bx has the perovskite cubic structure (space group Pm3m). Perovskite-type ScRh3Bx exists in the range of 0≦x≦1.000 (0 to 20 mol%B). ScRh3 has the AuCu3 type structure (space group Pm3m). The lattice parameter α in annealed ScRh3Bx depends on x, and varies linearly from α=0.3903 (1) nm (x=0) to 0.40799 (3) nm (x=1.000). The micro-Vickers hardness of the annealed ScRh3Bx increases with increasing B content in the range x=0-1.000, from 1.9(±0.1) GPa for ScRh3 (0 mol%B) to 9.9 (±0.1) GPa for ScRh3B1.000 (20 mol%B). TG analysis indicates that the onset temperature of oxidation for ScRh3B1.000 is 595°C. The sharp exothermic peak of the DTA curve is found at 797°C. Weight gain of the sample by heating in air up to 1200°C is 12.7%. The sample changed to Rh plus Sc2O3 and ScBO3 after oxidation. The weight gain of the sample decreases with decreasing boron content.
ASJC Scopus subject areas
- 化学 (全般)