Small-polaron hopping conduction in bilayer manganite La1.2Sr1.8Mn2O7

Article

关键词: MAGNETORESISTANCE;    TRANSPORT;    TEMPERATURE;    DISTORTION;   

DOI  :  10.1103/PhysRevB.67.094426

来源: SCIE

【 摘 要 】

We report anisotropic resistivity measurements on a La1.2Sr1.8Mn2O7 single crystal over a temperature T range from 2 to 400 K and in magnetic-fields H up to 14 T. For Tgreater than or equal to218 K, the temperature dependence of the zero-field in-plane resistivity rho(ab)(T) obeys the adiabatic small polaron hopping mechanism, while the out-of-plane resistivity rho(c)(T) can be ascribed by an Arrhenius law with the same activation energy. Considering the magnetic character of the polarons and the close correlation between resistivity and magnetization, we developed a model which allows the determination of rho(ab,c)(H,T). The excellent agreement of the calculations with the measurements indicates that small polarons play an essential role in the electrical transport properties in the paramagnetic phase of bilayer manganites.

【 授权许可】

Free