Constant Coupling Approximation for Amorphous Magnets

Abstract

Abstract The constant coupling approximation is used to determine the critical temperatures of amorphous ferro‐ and antiferromagnets, for both the Heisenberg and Ising model. Due to the structure fluctuations of the exchange integrals a decrease of the Curie temperature and the Néel temperature, respectively, are found in comparison with the corresponding crystalline case. This result agrees qualitatively with results of both the Green's function and the high‐temperature expansion treatments.