Study of the free energy of the La1-xCaxMnO3 manganites based on the temperature dependence of the crystal cell volume

Tang, G. D.; Liu, S. P.; Zhao, X.; Zhang, Y. G.; Ji, D. H.; Li, Y. F.; Qi, W. H.; Chen, W.; Hou, D. L.
September 2009
Applied Physics Letters;9/21/2009, Vol. 95 Issue 12, p121906
Academic Journal
A study of the free energy of the perovskite manganites was performed by fitting experimental results for the temperature dependence of the crystal cell volume using a detailed semiclassical model of the free energy. The fitted results coincide with the experimental results for the samples La1-xCaxMnO3 (x=0.2, 0.25, 0.3, and 0.5). The free energy includes the energy corresponding to thermal vibration of the crystal lattice, the ionic cohesive energy, and additional energies produced by electrical carriers from the double exchange mechanism and the thermal activation of small polarons.


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