Proceedings of the International Conference on Magnetism
J. Phys. Colloques 49 (1988) C8-67-C8-68
DOI: 10.1051/jphyscol:1988820
FUNCTIONAL INTEGRAL METHOD IN ITINERANT ELECTRON MAGNETISM
S. Hirooka1 et M. Shimizu21 Department of Electrical Engineering, Kagoshima University, Kagoshima 860, Japan
2 Sugiyama Jogakuen University, Nagoya 464, Japan
Abstract
Feynman's variational method and the arbitrariness of the Stratonovich-Hubbard transformation in the functional integral method are investigated. By making use of their results the dynamical spin susceptibility is given in the Gaussian approximation and it is applied to the calculation of the paramagnetic susceptibility of Ni.