Magnetodielectric effect without multiferroic coupling

TL;DR

This paper clarifies that magnetodielectric effects can occur without multiferroic coupling, arising from extrinsic effects like magnetoresistance and Maxwell-Wagner, which challenges their use as indicators of multiferroicity.

Contribution

It demonstrates that magnetocapacitance can result from non-multiferroic mechanisms, emphasizing the need for caution in interpreting such effects as evidence of multiferroic behavior.

Findings

Magnetodielectric effects can be caused by extrinsic resistive effects.

Magnetocapacitance is not a definitive indicator of multiferroicity.

Multiferroic coupling cannot be inferred solely from magnetodielectric measurements.

Abstract

The existence of a magnetodielectric (magnetocapacitance) effect is often used as a test for multiferroic behavior in new material systems. However, strong magnetodielectric effects can also be achieved through a combination of magnetoresistance and the Maxwell-Wagner effect, unrelated to multiferroic coupling. The fact that this resistive magnetocapacitance does not require multiferroic materials may be advantageous for some practical applications. Conversely, it also implies that magnetocapacitance per se is not sufficient to establish multiferroic coupling.