Effects of the spin and magnetic moments on the interaction energy between electrons. Application to ferromagnetism

TL;DR

This paper introduces a model incorporating magnetic moments and Heisenberg interactions to analyze electron interaction energies, successfully explaining ferromagnetic behavior and aligning with experimental Curie temperature data.

Contribution

The model uniquely combines magnetic moment interactions with Coulomb's law modifications, providing a better fit to experimental ferromagnetic data than previous models.

Findings

Triplet state has lower energy than singlet state.

Minimum interaction energy occurs for the triplet state.

Model accurately predicts Curie temperature.

Abstract

In this work we present a model for the determination of the interaction energy for triplet and singlet states in atoms with incomplete filled shells. Our model includes the modification of the Coulomb's law by the interaction between the magnetic moments of the electrons and a Heisenberg term. We find that the energy of the triplet state is lower than the energy of the singlet state. We calculate the interaction energy between the electrons from the adjacent atoms in fcc and bcc lattices and we find that the minimum interaction energy is attained for the triplet state. The result is presented for the interaction between the electrons of the first coordination group. The interaction energy which aligns the spins is used to evaluate the Curie temperature in a mean field model. Compared to previous models, our simple model fits the experimental data.