Large magnetocaloric effect induced by intrinsic structural transition in Dy 1− x Ho x MnO 3

We report the magnetic and magnetocaloric properties of Dy 1− x Ho x MnO 3 (0≤ x ≤1). Large entropy change of 12.5J/kg K and refrigeration capacity of 312J/kg at 7T for HoMnO 3 is calculated based on isothermal magnetization measurements. The peak temperature of magnetic entropy change for all samples keeps the same 10.5K, indicating that Ho 3+ doping only affects the value of magnetic entropy. An unambiguous intrinsic structural transition near 7K is first observed by strain measurement, which is believed as the origin of magnetic symmetry transition of Dy 1− x Ho x MnO 3 and induces the magnetocaloric effect with the cooperation interaction between Dy 3+ /Ho 3+ and Mn 3+ spins.