We report the experiment results and data analyses based on a polaron exchange model for La0.7Ca0.3MnO3 and Pr0.7(Sr1-xCax)0.3MnO3 epitaxial thin films. In the polaron exchange model with an energy balance condition, critical temperature of TC for stable ferromagnetic (FM) ordering should depend on ∆ E as kBTC =E0 exp(-ΔE/kBTC), where ∆ E denotes the potential barrier for the exchange polarons to overcome. Using the small polaron hopping model, the resistivity peak temperature TP is a function of the hopping energy Ehop. The dependence of TP on Ehop is similar to the dependence of TC on ∆ E, which reveals that the polaron exchange relates to FM and insulator--metal transitions. The result indicates that the polaron exchange model is a simple way for describing the FM ordering, and is very helpful for understanding of complex doped manganites.
We report the experiment results and data analyses based on a polaron exchange model for La0.7Ca0.3MnO3 and Pr0.7(Sr1-xCax)0.3MnO3 epitaxial thin films. In the polaron exchange model with an energy balance condition, critical temperature of TC for stable ferromagnetic (FM) ordering should depend on ∆ E as kBTC =E0 exp(-ΔE/kBTC), where ∆ E denotes the potential barrier for the exchange polarons to overcome. Using the small polaron hopping model, the resistivity peak temperature TP is a function of the hopping energy Ehop. The dependence of TP on Ehop is similar to the dependence of TC on ∆ E, which reveals that the polaron exchange relates to FM and insulator--metal transitions. The result indicates that the polaron exchange model is a simple way for describing the FM ordering, and is very helpful for understanding of complex doped manganites.
CHEN Li-Ping;MA Yu-Bin;SONG Xian-Feng;LIAN Gui-Jun;ZHANG Yan;XIONGGuang-Cheng. Relationship of Polaron Exchange with Ferromagnetic and Insulator--Metal Transitions in Doped Manganites[J]. 中国物理快报, 2008, 25(9): 3381-3384.
CHEN Li-Ping, MA Yu-Bin, SONG Xian-Feng, LIAN Gui-Jun, ZHANG Yan, XIONGGuang-Cheng. Relationship of Polaron Exchange with Ferromagnetic and Insulator--Metal Transitions in Doped Manganites. Chin. Phys. Lett., 2008, 25(9): 3381-3384.
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