NaV2O4: a Quasi-1D Metallic Antiferromagnet with Half-Metallic Chains

TL;DR

NaV2O4 is a quasi-one-dimensional material with metallic chains exhibiting half-metallicity, ferromagnetic intra-chain and antiferromagnetic inter-chain interactions, and a 3D antiferromagnetic order at 140 K, characterized through synthesis and various measurements.

Contribution

This work reports the synthesis and detailed characterization of NaV2O4 as a quasi-1D half-metallic antiferromagnet with unique magnetic and electronic properties.

Findings

Highly anisotropic resistivity with >20x difference

3D antiferromagnetic order at 140 K

Chains are half metallic according to calculations

Abstract

NaV2O4 crystals were grown under high pressure using a NaCl flux, and the crystals were characterized with X-ray diffraction, electrical resistivity, heat capacity, and magnetization. The structure of NaV2O4 consists of double chains of edge-sharing VO6 octahedra. The resistivity is highly anisotropic, with the resistivity perpendicular to the chains more than 20 times greater than that parallel to the chains. Magnetically, the intrachain interactions are ferromagnetic and the interchain interactions are antiferromagnetic; 3D antiferromagnetic order is established at 140 K. First principles electronic structure calculations indicate that the chains are half metallic. Interestingly, the case of NaV2O4 seems to be a quasi-1D analogue of what was found for half-metallic materials.