Observation of magnetocaloric and magneto-electric anomalies in R2Cu2O5 family of layered oxides

Abstract

R 2 Cu 2 O 5 (R = Tb-Lu, Sc, In) (RCO) compounds are interesting magnetic materials due to their quasi-low dimensional crystal structure, which also lacks centro-symmetry. Previous investigations on these compounds indicated antiferromagnetic or canted-antiferromagnetic ground state with Néel temperatures lying below about 30 K. The present work tries to provide finer details of the intricate magnetic characteristics of the RCO compounds, which were not addressed in the previous works. These include thermomagnetic irreversibility, thermal hysteresis , hysteresis in the isothermal magnetization measurements and so on. Most interestingly, we observe large magnetocaloric effect as calculated from our magnetization data and we find that it is primarily connected to the metamagnetic transitions observed in the samples. Our work also recognizes anomalies in the dielectric constant at the magnetic transition temperatures indicating possible multiferroicity in the samples. Efforts have been made to understand the diverse magnetic properties of the RCO samples on the basis of the crystal structure and the rare-earth moment. • A comprehensive magnetic scenario of complete R 2 Cu 2 O 5 series in a single report. • Observation of sizable magnetocaloric effect in R 2 Cu 2 O 5 associated with metamagnetism. • Dielectric anomaly at magnetic transition indicates the magneto-electric coupling. • Studies of thermo-magnetic irreversibility, thermal hysteresis in R 2 Cu 2 O 5 oxides.