Large magnetocaloric effect in La_2/3Ca_1/3Mn_1−<i>x</i>Si_<i>x</i>O₃(<i>x</i>= 0.05–0.20) manganites

Abstract

The magnetocaloric effect (MCE) in Mn site Si substituted La2/3Ca1/3Mn1?xSixO3 (x = 0.05, 0.10, 0.15 and 0.20) was investigated. All the samples have a single paramagnetic to ferromagnetic transition and show a large magnetic entropy change (??SM) in the vicinity of the Curie temperature (TC). With the increases in Si content x, the ??SM peak position as well as TC gradually shift to a low temperature, while the maximum value of the magnetic entropy change remains at nearly the same high value, in the range 4.88?5.48?J?Kg?1?K?1 and 8.78?10.32?J?Kg?1?K?1 for a magnetic field variation of 2?T and 7?T, respectively. The origin of the large MCE and its potential application were discussed. The present system appears to be a good candidate for magnetic refrigerant materials.