Structural, Magnetic and Magnetocaloric Properties of Pr0.68Ca0.32−xBixMnO3 (x = 0, 0.1, 0.18, 0.26 and 0.32) Compounds

The structural, magnetic and magnetocaloric properties of the polycrystalline Pr 0.68 Ca 0.32− x Bi x MnO 3 ( x = 0, 0.1, 0.18, 0.26 and 0.32) samples were studied. X-ray analyses indicated that all samples have a single phase of orthorhombic symmetry. The charge-order transition was observed for the x = 0 sample at T CO = 200 K, and it disappears with further Bi doping of the sample. The Curie temperature, saturation magnetisation and magnetocaloric effect decrease with increasing Bi content. The decrease in Curie temperature and saturation magnetisation was attributed to magnetic inhomogeneity and weakening of double-exchange interaction in the Bi-doped samples. The decrease in saturation magnetisation and the changed nature of phase transition give rise to a decrease in magnetic entropy change.