Direct and indirect measurement of the magnetocaloric effect in a La0.6Ca0.4MnO3 ceramic perovskite

The adiabatic temperature change DeltaT(ad) due to a change of the external magnetic field (the magnetocaloric effect) for a perovskite-type La0.6Ca0.4MnO3 sample has been measured directly and indirectly (from the entropy change) and the results are compared. From the indirect method, involving magnetic and calorimetric measurements, a maximum temperature change of approximately 0.54K can be expected with a field change of 0.7T. Considering experimental errors, this is in fairly good agreement with the direct temperature measurement, where a maximum temperature change of about 0.5 K was observed with a corresponding change of the applied field. The experimental results are in accordance with theoretical estimates obtained from a mean field theory. (C) 2002 Elsevier Science B.V. All rights reserved.