The composition dependence of magnetization and curie temperature of Fe-P, Co-P and Ni-P

Abstract

The saturation magnetization σ 0 of electrodeposited Fe-P, Co-P and Ni-P (0–27 at% P) alloys at low temperatures has been measured with a vibrating sample magnetometer while the Curie temperatures T c have been derived from the breakdown of the magnetic moments induced by a small external field. The magnetic moment per atom decreases linearly with growing phosphorous content. The facts that the slopes of the lines are the same for the three alloy systems and that their values are smaller than predicted do not fit to known theoretical models, e.g. to modified rigid band models and to the valence bond model. Ni-P and Co-P behave similarly, as the extrapolation of the corresponding straight lines to zero phosphorous content reveals the known σ 0's and T c's of the pure crystalline metals. This is not true in the case of Fe-P. These observations allow some conclusions concerning the short range order in the three alloy systems.