CdV2O4: A rare example of a collinear multiferroic spinel

TL;DR

This study reveals that CdV2O4 exhibits multiferroicity driven by local magnetostriction in a collinear antiferromagnetic state, supported by experimental dielectric measurements and ab-initio calculations, highlighting charge rearrangement effects.

Contribution

It provides a rare example of a collinear multiferroic spinel where ferroelectricity arises from local magnetostriction, not spiral magnetism, supported by experimental and theoretical evidence.

Findings

Ferroelectricity develops at the antiferromagnetic transition.

Charge rearrangement due to dimerization is observed.

Electronic correlations influence the multiferroic behavior.

Abstract

By studying the dielectric properties of the geometrically frustrated spinel CdV2O4, we observe ferroelectricity developing at the transition into the collinear antiferromagnetic ground state. In this multiferroic spinel, ferroelectricity is driven by local magnetostriction and not by the more common scenario of spiral magnetism. The experimental findings are corroborated by ab-initio calculations of the electric polarization and the underlying spin and orbital order. The results point towards a charge rearrangement due to dimerization, where electronic correlations and the proximity to the insulator-metal transition play an important role.