A Calculation on the Temperature Variation of the Magnetization for Ni Metal

Abstract

A calculation on the temperature variation of the magnetization for Ni metals performed by the Stoner theory, by making use of the density of states curve which was determined from low temperature specific heat data. The effective exchange energy is expanded as a power series of the magnetization, M, and the values of coefficients are estimated from the comparison between calculated and experimental results of the M vs T curve. In order to explain the experimental results for the temperature variation of M in Ni metal, the terms of the higher power of M than the quadratic term in the exchange energy must be taken into account. Our density of states curve is not similar to the normal band used by Stoner and the rectangular band used by Wrohlfarth, nevertheless the calculated results for the temperature variation of M are similar to each other. It is shown that there is a Possibility that a first order transition of magnetization occurs.