The pseudobinary alloy Hf0.82Ta0.18Fe2 was prepared by arc melting and annealing technique. X-ray powder diffraction indicated a C14-type Laves phase structure with the crystal parameters a = 4.92133(3) and c = 8.0488(1). The Mssbauer spectra were measured at different temperatures between 20 K and 380 K
and showed two magnetic phase transitions
one from paramagnetic state to antiferromagnetic state at about 330 K and the other from antiferromagnetic state to ferromagnetic state at about 180 K. The latter transition indicated a spin-reorientation for 6h site Fe atoms
thus
the Fe atom spin at 6h turn to ab plane from c axis. However
the Fe atoms at 2a also showed a magnetic moment in ferromagnetic state.