Calculation of the Spin Wave Energy of Iron, Cobalt and Nickel

Abstract

The spin wave energies for iron, cobalt and nickel are computed in the long wave length limit and in the random phase approximation, using the results of band structure calculations. The energy expression and the criterion for the stability of the ferromagnetic ground state are give in terms of a function M(ε), a surface integral involving the gradient of the single particle energy. The results obtained indicate the possible importance of the s-p band in stabilizing the ferromagnetic ground state. Agreement with experimental values of the spin wave energy is very good for nickel, but for cobalt and iron the calculated values are much smaller than those observed.