Influence of the magnetic two-phase state on the magnetocaloric effect in manganites

The magnetocaloric effect DeltaT(ex) and magnetization were studied for single crystals La1-xSrxMnO3. From the magnetization the magnetocaloric effect DeltaT(th) was computed. The temperatures of maxima on the curves DeltaT(ex)(T) are observed on 20-40 K above, than the ones on the curves DeltaT(th)(T). It is explained by the presence of magnetic two-phase ferro- antiferromagnetic state in a crystal. The DeltaT(ex)-value equal to the sum of contributions from ferromagnetic and antiferomagnetic parts of crystals that have positive and negative signs correspondingly, whereas DeltaT(th)-value is determined by ferromagnetic part of a crystal. (C) 2003 Elsevier B.V. All rights reserved.