Article ID Journal Published Year Pages File Type
1648928 Materials Letters 2010 4 Pages PDF
Abstract

In the present work we analyze the magnetic entropy change ΔSM of La0.8Pb0.1MnO3 (LPMO) and La0.8Pb0.1Na0.1MnO3 (LPNMO). Using Arrott plots, it was found that the phase transition for both samples is of second-order. The presence of short-range magnetic order (SRMO) in the paramagnetic phase of these samples greatly depresses the magnetic entropy: the ΔSMmax values are well below the values expected without considering the effect of SRMO. Moreover, the analysis of the MCE using Landau theory of phase transition shows that the contributions to the free energy from the presence of ferromagnetic clusters are strongly influencing the MCE by coupling with the order parameter around the Curie temperature.

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Physical Sciences and Engineering Materials Science Nanotechnology
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