Abstract
We report magnetization, magnetic entropy change (ΔS m ), and its correlation with magnetoresistance (MR) in Pr 0.58 Sr 0.42 MnO 3. It is shown that the magnetization upon field-cooling shows a steplike decrease at T S 134 K much below the ferromagnetic transition (T C 300 K). While the low temperature transition is first-order, the high temperature transition is second-order as suggested by the hysteresis behavior in magnetization. In a magnetic field range accessible with an electromagnet, the magnetic entropy decreases at T C (ΔS m -2.33 J/kg K with a refrigeration capacity of 65.88 J/kg for a magnetic field change of ΔH 2 T) whereas it increases at T S (ΔS m 0.7 J/kg K) upon magnetization. The unusual inverse magnetocaloric effect found at T S within ferromagnetic state is ascribed to orthorhombic to monoclinic structural transition. We show that ΔS m versus T curves under different magnetic fields can be collapsed into a single master curve using a scaling method. Importantly, we find that negative MR increases linearly with -ΔS m in the paramagnetic state at all magnetic fields above T C and at higher magnetic fields below T C . Such a close correlation between the magnetoresistance and the magnetic entropy change can be exploited to design efficient magnetocaloric materials.
Original language | English |
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Article number | 17A906 |
Journal | Journal of Applied Physics |
Volume | 113 |
Issue number | 17 |
DOIs | |
Publication status | Published - 7 May 2013 |
MoE publication type | A1 Journal article-refereed |