Polar properties of Eu0.6Y0.4MnO3 ceramics and their magnetic field dependence

Eu1-xYxMnO3 exhibits, unlike other magnetoelectric systems, very distinctive features. Its magnetoelectric properties is driven by the magnetic spin of the Mn3+ ion, but they can be drastically changed by varying the content of Y3+, which it does not carry any magnetic moment. Though the x = 0.40 composition has been studied extensively, some basic questions still remain to be thoroughly understood. Thus, this work is aimed at studying some of its polar properties and their magnetic field dependence as well. The experimental results here reported have shown that this material is very easily polarisable under external electric fields, and so, whenever the polarization is obtained from time integration of the displacement currents, an induced polarization is superposed to the spontaneous one, eventually masking the occurrence of ferroelectricity. We have found clear evidence for the influence of a magnetic field in the polar properties of Eu0.6Y0.4MnO3. The study of electric polarization of Eu0.6Y0.4MnO3 under an external magnetic field yields a value with the same order of magnitude of the remanent polarization determined from polarization reversal experiments. The comparison of the magnetic induced changes on the polarization obtained in polycrystalline samples and single crystals confirms the threshold magnetic field value for the polarization rotation from the a- to the c-direction, and evidencing the importance of the granular nature of the samples in the polar response to magnetic field.