Magnetodielectric effect in CoCr2−XFeXO4

Abstract

Conventional multiferroics show the multiferroic behaviors below two successive transitions (a ferroelectric transition and a ferromagnetic transition). In the present study, we report the magneto-dielectric (MD) effect (both in-plane and out-of-plane) in CoCr2−XFeXO4 which undergoes only a ferromagnetic transition. We found the MD effect in the pure ferromagnetic phase (TS<T<TC) of CoCr2O4. And such MD effect is temperature dependent. The magnitude of the MD effect gradually decreases with approaching Curie temperature (TC) and finally becomes zero at TC. With doping Fe into CoCr2O4, we found the magnitude of MD effect increases and the MD effect exists in a wider temperature region because TC increases and TS decrease with doping Fe. Our results show the coupling between the ferromagnetic and ferroelectric orders. It suggests that both the ferromagnetic and ferroelectric properties originate from the same transition.