Magnetic structure and phase composition of microinhomogeneous PdMn x Fe1 − x alloys

Mössbauer analysis of ternary PdMn _x Fe_{1 ? x} alloys in the range of concentrational transition from a ferromagnetic PdFe (F ₁) (T _C = 725 K) to an antiferromagnetic PdMn (A) (T _N = 815 K) phase has been carried out at temperatures T ～ 80 and 295 K. An estimation of the relative volumes of the ferromagnetic and antiferromagnetic ordered phases in the molecular-field approximation was performed via calculation of the magnetic susceptibility of the alloy with x = 0.5; an analysis of the microstructure of the alloy with x = 0.45 was performed using the Bitter-figures technique. For the alloys with extreme concentrations, Mössbauer spectra have been obtained in two different forms, i.e., a doublet with H _hf < 50 kOe for the antiferromagnetic alloys with x > 0.8 and a sextet with H _hf ～ 350 kOe for the ferromagnetic alloys with x < 0.2. In the intermediate concentration range, a wide spectrum of hyperfine fields 0 < H _hf < 350 kOe has been observed, which is due to a microinhomogeneous multiphase state.