Structure, magnetic and magnetocloric properties of Pr 0.7Ca 0.3Mn 1-yCr yO 3

Abstract

Pr 0,7Ca 0,3Mn 1-yCr yO 3 compounds (with 0≤y≤0.20) have been prepared by means of the solid-state reaction, from stoichiometric powder mixtures of binary oxides, at high temperatures in ambient air. The samples were studied by X-ray powder diffraction analysis. The structural refinement using the Rietveld method based on the FULLPROF program shows that our polycrystalline specimens are single phase and crystallize in the orthorhombic structure with Pnma space group. Magnetic measurements versus temperature and versus magnetic field were also performed in all compounds. The Cr substitution in Pr 0,7Ca 0,3Mn 1-yCr yO 3 is found to induce a ferromagnetic behavior at low temperatures. From isothermal magnetization curves, we can determine the magnetocaloric effect, which is of utmost important in the magnetic refrigeration technique. These results may open an important field in the search of new magnetic materials for magnetic refrigeration in order to replace the conventional expansion-compression technique. © Published under licence by IOP Publishing Ltd.