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 Caconcentration 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 ( ), 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.

Keywords: Magnetic refrigeration, Magnetocaloric effect, Entropy, Manganites