Colossal magnetocapacitive effect in differently synthesized and doped CdCr2S4

TL;DR

This study investigates the origin of the colossal magnetocapacitive effect in CdCr2S4, demonstrating it occurs independently of chlorine impurities and can be induced in chlorine-free, doped ceramic samples, suggesting an intrinsic mechanism.

Contribution

It reveals that the colossal magnetocapacitive effect in CdCr2S4 is not due to chlorine impurities and can be achieved through doping and synthesis methods, indicating an intrinsic origin.

Findings

Magnetocapacitive effects occur without chlorine impurities.

Doping with indium in chlorine-free samples induces the effect.

Effect is observed below magnetic transition temperature and in magnetic fields.

Abstract

In the present work, we address the question of an impurity-related origin of the colossal magnetocapacitive effect in the spinel system CdCr2S4. We demonstrate that a strong variation in the dielectric constant below the magnetic transition temperature or in external magnetic fields also arises in crystals prepared without chlorine. This excludes that an inhomogeneous distribution of chlorine impurities at the surface or in the bulk material gives rise to the unusual effects in the spinel multiferroics. In addition, we show that colossal magnetocapacitive effects can be also generated in chlorine-free ceramic samples of CdCr2S4, doped with indium.