Magnetocapacitance effect in nonmultiferroic YFeO3 single crystal

YFeO3 single crystal displays two relaxor-like dielectric relaxations, one at low temperature (170 300 K) and one at high temperature (370 520 K), which are attributed to the activation of electrons and oxygen vacancies, respectively. Above the temperature at which electrons are activated, the sample displays a large magnetocapacitance effect. Comparison of the impedance Cole-Cole plots measured with and without applied magnetic field reveals that the occurrence of magnetocapacitance effect is accompanied with an increasing in DC conductivity under magnetic field after the activation of electrons, which is explained by the enhancement of electron jumping in Fe2+-O-Fe3+ chains by magnetic field. Thus the magnetocapacitance effect in YFeO3 single crystal can be explained by the combination of the Maxwell-Wagner space charge effect and/or magnetoresistance effect, depending on the frequency range. (C) 2012 American Institute of Physics. [doi:10.1063/1.3681294]