Electron doping induced exchange bias and cluster glass magnetism in multiferroic Sc0.8Zr0.2MnO3

Since few decades, several studies on hole-doping in rare-earth manganites (RMnO3) have been reported exploring various novel phenomena. Comparatively electron-doping studies in RMnO3 are scarcely found and the intrinsic properties are still unidentified. We report on the occurrence of exchange bias phenomenon and glassy magnetic interaction in multiferroic compound Sc0.8Zr0.2MnO3 induced by electron doping. The compound possesses long-range antiferromagnetic ordering, (TN = 90 K) and electron doping was found to induce additional ferromagnetic interaction (TC = 60 K) in it. The study provides compelling experimental evidences that the system behaves more like a cluster glass compound than a canonical spin glass system with a freezing temperature (Tf) of 13 K. Field-cooled magnetic hysteresis loops are found to shift in the field axis (HE) and show asymmetry in remanent magnetization (ME). The direction of loop shift depends on the sign of the cooling field used. We present details of field cooling and temperature dependence of HE and ME and training effect in Sc0.8Zr0.2MnO3. A comparison with the commonly observed exchange bias phenomena in typical phase separated systems is also presented. The present study assumes significance as it helps the understanding of new phenomena consequent to electron doping.