Mössbauer study of the spin reorientation in pseudobinary alloy Hf0.82Ta0.18Fe2

Hf1−xTaxFe2 pseudobinary alloy with x = 0.18 was prepared. It was found to crystallize in C14 type Laves phase structure examined by X-ray diffraction (XRD). Mössbauer spectra at varied temperatures show there are two transition temperatures, one for paramagnetic (PM) to antiferromagnetic (AFM) state at about 330 K, and the other for AFM to ferromagnetic (FM) state at about 180 K. In the latter transition, spin reorientation is observed. The spin of Fe magnetic moment at 6h is along c axis in AFM state while lie close to ab-plane in FM state. No magnetic interaction at 2a site is found in AFM state but FM. The hyperfine field anisotropy at 6h site in FM state is also analyzed.