Abstract
We report the magnetic transition and large magnetic entropy change in calcium doped lanthanum manganites. Polycrystalline La1-xCaxMnO3 (0 <= x >= 0.4) samples were prepared by the conventional solid-state reaction technique. The X-ray diffraction analysis exhibits only the perovskite phase without any impurity. It was found that the Curie temperature is varied with the Ca-concentration because of the doping of Ca at La site affects the Mn-O bond length and Mn-O-Mn bond angle due to the difference in their ionic radii. A large magnetic entropy change was observed in the La0.7Ca0.3MnO3 sample and the value of the maximum entropy change (vertical bar Delta S-M(max)vertical bar), increase from 4.67 to 10.78 J/kgK as magnetic field increases from 1 to 5 tesla. This result suggests that La0.7Ca0.3MnO3 can be used as a potential magnetic refrigeration material.