Mössbauer Study of Reentrant Spin-Glass Pd_1−x−yFe_xMn_y: Evidence for Coexistence of Spin-Glass and Ferromagnetic Orderings

Abstract

The Mössbauer study has been made on the reentrant spin-glass state of Pd_0.881Fe_0.027Mn_0.092 and Pd_0.930Fe_0.015Mn_0.055. The anomalous increase of the average hyperfine field \barH_hf, found in some alloys with the reentrant spin-glass transition, was clearly observed below the spin-glass transition temperature T_g. This can be explained as freezing of the transverse spin component at T_g. From the variation of the Mössbauer absorption intensity ratios with applied field, it has been shown that Fe spins behave partly ferromagnetic and partly like a spin-glass. We consider that this fact is an evidence for the coexistence of the spin-glass and ferromagnetic orderings. A model to explain our results has been proposed. It has been also shown that the spin-glass state is microscopically not much affected by magnetic fields up to 5 kOe, the maximum value examined.