Magnetic Properties of Amorphous Pd–Si Alloys Containing Iron

Abstract

Magnetic properties of amorphous Fe_xPd_80−xSi₂₀ alloys (x=0.5–7) obtained by rapid quenching from the liquid state are studied between 1.5° and 300°K and in fields up to 8.40 kOe. The amorphous alloys are paramagnetic above the characteristic temperature T_d. The observed magnetic moments can be explained by postulating a simple magnetic domain consisting of one Fe atom and its Pd nearest neighbors. This is consistent with the magnetic moments assigned to each Fe atom (μF_e=3.0μ_B) and to each Pd atom (μPd=0.20μ_B). Below T_d superparamagnetic clusters exist in the amorphous alloys. Ferromagnetism is found in amorphous Fe₇Pd₇₃Si₂₀ alloys with a Curie temperature of 28°K. Evidence is discussed which demonstrates that the d‐d spin exchange interaction is weaker in the amorphous alloys than in the corresponding crystalline alloys.