Study of Magnetocaloric Effect in (1—y)La_0.7Sr_0.3MnO₃/(y) Mn_0.5Zn_0.5Fe₂O₄ Composite

다국어 초록 (Multilingual Abstract)

<P>The structural, magnetic and magnetocaloric properties of (1-y)LSMO/(y)Mn0.5Zn0.5Fe2O4 (y = 0.00, 0.03, 0.05, 0.10) composite samples have been studied. All samples show mainly pervoskite phase with rhombohedral crystal lattice. The XRD peaks of Mn0.5Zn0.5Fe2O4 phase were not observed because of its very low concentration in the composite sample. The magnetization measurement reveals that the Curie temperature, T-C decreases significantly with increasing the Mn0.5Zn0.5Fe2O4 concentration in the composite samples. On the other hand, the temperature range of paramagnetic-ferromagnetic transition becomes broader in case of composite samples. The magnetic entropy evaluation shows that the Delta S-M(max) decreased in case of composite samples as compared to that of pure LSMO sample. In addition, an enhanced relative cooling power of 57 J/kg (at 1 T) was observed for the (0.97) LSMO/(0.03)Mn0.5Zn0.5Fe2O4 composite sample, which is due to the increased partial derivative T-FWHM over 62 K around room temperature.</P>