Magnetocaloric properties of Cd-substituted perovskite-type manganese oxides

Polycrystalline samples of cadmium-doped lanthanum manganites having nanometric crystallite size have been synthesized by sol-gel method. The Curie temperature (T-C) of the prepared samples is found to be strongly dependent on Cd content and spans between 253 and 270 K. The Curie temperature has been analysed by two methods: a linear extrapolation of M(T) to zero magnetization and the thermodynamic model. Close to T-C, a large change in magnetic entropy has been observed in all the samples. With increasing Cd concentration, a systematic increase in the values of magnetic entropy is observed (1.8 <= vertical bar Delta S-m(max)vertical bar <= 2.33 J/(kg K)) with H = 10 kOe. Our result about magnetocaloric properties suggests that La1-xCdxMnO3 compounds are suitable for sub-room temperature magnetic refrigeration. (c) 2008 Published by Elsevier B.V.