Solid solution range of boron, microhardness and magnetic properties of the perovskite-type GdRh3B obtained by arc-melting synthesis

Polycrystalline samples of GdRh3Bx were synthesized using the are-melting method. A compound of GdRh3Bx has a perovskite-type cubic structure (space group: Pm3m) in which. the concentration of boron is distributed between a: = 1.000 (20 at%B) and 0.444 (10at%B) for GdRh3Bx. The lattice parameter a of GdRh3Bx depends on x and varies linearly from a = 0.41831(6) nm (x = 1.000) to 0.4121(1) nm (x = 0.444). The micro-Vickers hardness of GdRh3Bx increases with increasing B content in the range of x = 0.444 similar to 1.000, and hardness of the GdRh3B0.444 and GdRh3B1.000 is 3.4 (+/-0.12) and 6.8 (+/-0.08) GPa, respectively. The stoichiometric compound GdRh3B has a ferromagnetic property with the Curie temperature of 14 K.