Method of effective potential for quantum Heisenberg ferromagnet theory

TL;DR

This paper develops a functional method to model the temperature-dependent magnetization in quantum Heisenberg ferromagnets, achieving good agreement with experimental data for EuO, especially outside the critical temperature region.

Contribution

It introduces a self-consistent perturbation approach using functional methods to analyze quantum ferromagnets, providing accurate predictions of magnetization and Curie temperature.

Findings

Quantitative agreement with experimental magnetization data for EuO.

Accurate prediction of Curie temperature within a few percent.

Critical behavior modeled near the Curie point.

Abstract

Self - consistent temperature dependence of the average magnetization in quantum Heisenberg ferromagnet is obtained as a first approximation of perturbation theory on an inverse radius by application of the functional method for quantum ferromagnet. The experimental data are compared with the theoretical results for {\bf EuO} ferromagnet. A quantitative agreement is observed between theoretical and experimental results outside interval near Curie temperature. The theory is of critical behavior in the vicinity of Curie temperature $T_c$. Theoretical $T_c$ value itself is agreed with the experimental one with an accuracy of several percents.