LARGE MAGNETIC ENTROPY CHANGE NEAR CHARGE-ORDERED TRANSITION TEMPERATURE IN PEROVSKITE-TYPE MANGANITE

The magnetocaloric effect in polycrystalline of Pr_1-xSr_xMnO₃ (x=0.33, 0.43, 0.50) has been investigated. A large magnetic entropy change (7.1J/kgK) was discovered in Pr_0.5Sr_0.5MnO₃ under a low magnetic field of 1T at charge-ordered state transition temperature (161K). The physical mechanism is related to a drastic magnetization change at a temperature where the field-induced magnetic, electron and structural phase transitions occur (from the antiferromagnetic charge-ordered state to the ferromagnetic charge-disordered state).