Crystal structure and magnetic properties of SmCo7−xHfx compounds

Abstract

The crystal structure and magnetic properties of SmCo7−xHfx (x=0.05,0.1,0.2,0.3) compounds were studied by means of x-ray powder diffraction and magnetic measurements. The as-cast compounds SmCo7−xHfx with x=0.1 and 0.2 crystallize in the TbCu7-type structure with the space group P6∕mmm. According to the structure refinement, the doping element Hf prefers to occupy the 2e site. The compounds have high Curie temperatures (1080K for x=0.1, 1075K for x=0.2), large saturation magnetization (104emu∕g for x=0.1, 102emu∕g for x=0.2 at 5K), and large magnetic anisotropy fields (244kOe for x=0.1, 282kOe for x=0.2 at 5K) with strong uniaxial magnetocrystalline anisotropy.