Magnetism and electronic structure calculation of SmN

TL;DR

This paper investigates the electronic structure and magnetism of SmN using LDA+U calculations, revealing a half-metallic state without spin-orbit coupling and an antiferromagnetic semiconducting state with spin-orbit coupling, aligning with experiments.

Contribution

It provides detailed electronic and magnetic structure calculations of SmN, highlighting the effects of spin-orbit coupling on its ground state, which was not previously well understood.

Findings

SmN exhibits a half-metallic ground state without spin-orbit coupling.

Including spin-orbit coupling results in an antiferromagnetic semiconducting ground state.

Calculated magnetic moments align with experimental observations.

Abstract

The results of the electronic structure calculations performed on SmN by using the LDA+U method with and without including the spin-orbit coupling are presented. Within the LDA+U approach, a N(2$p$) band polarization of $\simeq 0.3\ \mu_B$ is induced by Sm(4$f$)-N(2$p$) hybridization, and a half-metallic ground state is obtained. By including spin-orbit coupling the magnetic structure was shown to be antiferromagnetic of type II, with Sm spin and orbital moments nearly cancelling. This results into a semiconducting ground state, which is in agreement with experimental results.