不定比性ペロブスカイト型化合物GdRh_3B_xの硬度と耐酸化性

概要

論文の詳細を見る
Polycrystalline samples of GdRh_3B_x, which consists of highly reactive(Gd)and high melting(Rh, B)elements, have been successfully synthesized by arc melting method. Extreme evaporation of the constituent elements has not been observed. Compound of GdRh_3B_x has perovskite type cubic structure(space group : Pm3m). Perovskite-type GdRh_3B_x exists in the range of x=1.000(20 atom% B)and 0.444(10 atom% B). Lattice parameter of a in annealed GdRh_3B_x depends on x, and varies lineary from α=0.41831(6)nm(x=1.000)to 0.4121(1)nm(x=0.444). The TG curve indicates that the onset-temperature of oxidation for GdRh_3B_<1.000> is 567.3℃ and for GdRh_3B_<0.706> is 611.3℃, respectively. Weight gain by heating in air up to 1200℃ for GdRh_3B_<1.000>(20 atom% B)is 6.83% and for GdRh_3B_<0.706>(15 atom% B)is 8.61%, respectively. The former value for stoichiometric compound is smaller than the latter. Both samples decompose to GdBO_3 and Rh after oxidation. The micro-Vickers hardness of the annealed GdRh_3B_x increases with increasing B content in the range of x=1.333-0.444, for example hardness of the annealed GdRh_3B_<1.000>(20 atom%B)is 4.2(±0.10)GPa.
社団法人日本セラミックス協会の論文
1998-01-01