Structural, magnetic and magnetocaloric properties of La0.7Sr0.3MnO3 manganite oxide prepared by the ball milling method

Structural, magnetic and magnetocaloric properties of La0.7Sr0.3MnO3 sample have been investigated. Powder sample has been elaborated by the ball milling method. The Rietveld analysis of the powder X-ray diffraction shows that the sample crystallizes in the orthorhombic structure with Pnma space group. Magnetic measurements showed that the sample exhibits a ferromagnetic-to-paramagnetic transition at a Curie temperature close to 370 K. The magnetic entropy change (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$ \Delta S_{M}$\end{document}) has been deduced by the Maxwell relation method. The maximum value of the magnetic entropy change \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$| \Delta S_{M}^{\max} |$\end{document} is found to be 1.1 J/kgK for an applied magnetic field of 2T. At this value of magnetic field the relative cooling power (RCP) is 49 J/kg. At high temperature, large change in magnetic entropy has been observed in the sample. Our result on magnetocaloric properties suggests that La0.7Sr0.3MnO3 nanopowder is attractive as a possible refrigerant for high temperature magnetic refrigeration.