【摘 要】
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We report the experiment results and data analyses based on a polaron exchange model for La0.7 Ca0.3 MnO3and Pr0.7(Sr1-xCax)0.3 MnO3 epitaxial thin films. In th
【机 构】
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School of Physics, Peking University, Beijing 100871
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We report the experiment results and data analyses based on a polaron exchange model for La0.7 Ca0.3 MnO3and Pr0.7(Sr1-xCax)0.3 MnO3 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 κBTC =Eo exp(-△E/κkBTC), 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.
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