The effect of 3d-transition metal solutes on the ferrimagnetism of Fe 7Se 8

Abstract

The effect of 3d-transition metal solutes on the magnetization of Fe 7Se 8 has been investigated by studying two series of alloys with constant solute concentrations of 3 and 10 at%, respectively. Small additions of Ti and V were sufficient to reduce the magnetization by one order of magnitude, whereas Ni slightly increased the magnetization. The changes due to the presence of Cr, Mn and Co were less noticeable. In certain cases the thermal treatment turned out to be a decisive factor in determining the type of magnetism. Alloys with Cr quenched from 1070 K were clearly antiferromagnetic. Quenched samples containing ten percent Ti were paramagnetic following a Curie-Weiss type law, but slow cooling from 1070 K reestablished the ferrimagnetic state. Order-disorder phenomena were assumed to be responsible for the changes due to the thermal treatment.