Low-temperature transport in La0.5Ca0.4Li0.1MnO3 manganite in high magnetic fields (1 T ⩽ H ⩽ 14 T)

Resumo

The low-temperature minimum of the resistivity of La_0.5Ca_0.4Li_0.1MnO₃ manganite in high magnetic fields (up to 14 T) is analyzed quantitatively. It is shown that the behavior of the resistivity and magnetoresistance at low temperatures is successfully described by the model of intergrain spin-polarized tunnel charge transfer. In accordance with this model, the resistivity is expressed in terms of the correlation function of magnetizations of neighboring grains. The expression for the temperature- and magnetic-field dependences of this correlator, derived in [31], is thoroughly analyzed and applied for the polycrystalline manganite sample under investigation. The main parameters of the chosen model are obtained from analysis of experimental data.