Large magnetocaloric effect in hexagonal Yb < inf > 1-x < /inf > Ho < inf > x < /inf > MnO < inf > 3 < /inf >

Abstract

Magnetocaloric properties of polycrystalline hexagonal Yb1-xHoxMnO3 (x = 0.1, 0.2, and 0.3) compounds are studied through magnetization measurements. Temperature dependence of Zero Field Cooled magnetic moment measurements shows Néel temperature (TN1) of ∼83 K, corresponding to the Mn3+ antiferromagnetic ordering. At low temperatures (TN2 ∼ 5 K), all compounds show ferromagnetic ordering due to alignment of the Yb moments and the field induced magnetic transition is observed in the isothermal magnetization measurements. The maximum entropy change |ΔSMmax| and the relative cooling power (RCP) of Yb1-xHoxMnO3 are 3.75 ± 0.78 J/(mol K) and 90.0 ± 27 J/mol for x = 0.3 at ΔH = 100 kOe. Values of both |ΔSMmax| and RCP found to increase with increasing Ho content.