Spin Density Functional Based Search for Half-Metallic Antiferromagnets

TL;DR

This study uses spin density functional calculations to identify potential half-metallic antiferromagnetic materials in double perovskite oxides, highlighting promising candidates like La2VMnO6 and La2VCuO6.

Contribution

It introduces a computational approach to discover half-metallic antiferromagnets in double perovskite structures, identifying specific promising compounds.

Findings

La2VMnO6 is a stable candidate with a 0.17 eV/cell energy difference favoring the HM AFM phase.

La2VCuO6 is another promising candidate, with quantum fluctuations potentially influencing its magnetic state.

Half-metallic antiferromagnetic materials are more accessible to find than previously thought.

Abstract

We present results based on local spin density calculations of a computational search for half-metallic (HM) antiferromagnetic (AFM) materials within the class of double perovskite structure oxides LaM'M''O3 that incorporate open shell 3d (or 4d) transition metal ions M', M''. The pairs M'M'' = MnCo, CrFe, CrRu, CrNi, MnV, and VCu are studied. La2VMnO6 is the most promising candidate, with the HM AFM phase more stable by 0.17 eV/cell than the ferromagnetic phase. La2VCuO6 is another promising possibility, but due to S=1/2 ions quantum fluctuations my play an important role in determining the ground state magnetic and electronic structure. This study indicates that HM AFM materials should not be prohibitively difficult to find.