The Curie Temperatures of Magnetically Dilute Ferromagnetics

Abstract

By the method of concentration expansion, the initial gradient I_g for a curve of the Curie temperature θ_c(p) vs the concentration p of magnetic ions in randomly dilute Ising ferromagnet is calculated. The calculation is performed for the eight kinds of crystal lattices and the results are discussed with particular emphasis as to its dependence on the crystal structure and the second neighbor interactions. Various experimental data are compared with the present results of I_g together with the other critical properties p_c, θ_c(p) obtained in the previous paper. As a whole, the behaviors of θ_c(p) determined experimentally are well explained by the theory, and an importance of the second neighbor interactions is indicated for some compounds.