Large magnetic entropy change near room temperature in La 0.7 (Ca 0.27 Ag 0.03 )MnO 3 perovskite
- Citation data:
Journal of Alloys and Compounds, ISSN: 0925-8388, Vol: 509, Issue: 8, Page: 3699-3704
- Publication Year:
- Engineering; Materials Science; Large; magnetic; entropy; change; near; room; temperature; Ca0; 27Ag0; MnO3; perovskite; Physical Sciences and Mathematics
In this paper, the magnetic properties and magnetocaloric effect (MCE) of La 0.7 (Ca 1−x Ag x ) 0.3 MnO 3 ( x = 0, 0.1, 0.2, 0.7, and 1) powder samples are reported. Our polycrystalline compounds were synthesized using the solid state reaction method at high temperature. Magnetization measurements versus temperature showed that all our samples exhibited a paramagnetic to ferromagnetic transition with decreasing temperature. The Curie temperature, T C, has been found to increase from ∼250 K for x = 0–270 K for x = 1. Ag doping weakens the first order phase transition, and at higher Ag doping, the phase transition is of second order. For the La 0.7 (Ca 0.27 Ag 0.03 )MnO 3 composition, the maxima of the magnetic entropy changes from the applied magnetic field (Δ S M ) at 2 and 5 T are about 4.5 and 7.75 J/kg K, respectively, at the Curie temperature of ∼263 K. The relative cooling power (RCP) values without hysteresis loss are about 102 and 271 J/kg for the applied fields of 2 and 5 T, respectively. Due to the large Δ S M, large RCP, and high Curie temperature, La 0.7 (Ca 0.27 Ag 0.03 )MnO 3 is promising for application in potential magnetic refrigeration near room temperature.