Magnetization, dielectric and thermal studies in the double perovskite polycrystalline compound Tm2CoMnO6

Abstract

We report here a comprehensive study on structural, magnetic, caloric and electronic properties of the monoclinic phase of double perovskite compound Tm2CoMnO6 (TCMO) in its polycrysttaline format. Magnetic measurements confirm the presence of thermal hysteresis in magnetization indicates towards a first order magnetic transition at its critical point (Tc). Our study finds the metamagnetic jump in isothermal M(H) at 2 K that signifies the rare earth spin allignement in loop cycling above a certain critical field. This jump is only present at very low T that dies out as the T raises. M(H) measurements at different temperature stipulate that Co2+ and Mn4+ do not order completely inspite of strong ferromagnetic correlation that is against the previous study on TCMO. The concurrence of structral, magnetic and dielectric anomaly at Tc suggest its possible magnetostructural copuling. We found a high dielectric constant (2700) in TCMO and the Maxwell-Wagner electrial loss spectrum analysis hints towards a long range hopping mechanism. Sizeable magnetocaloric effect in terms of entropy change across the transition temperatures has been obtained from heat capacity data that clearly corroborates its intrinsic behaviour.