Electrical and magneto transport properties of La$_{0.8−x}$Ca$_x$Sr$_{0.1}$Ag$_{0.1}MnO$_3$ ($x = 0.1, 0.2, 0.3$)

Bulletin of Materials Science

关键词: X-ray diffraction;    colossal magneto resistivity;    phase separation;    weak localization;    variable range hopping.;   

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

Lanthanum-based manganites La$_{0.8−x}$Ca$_x$Sr$_{0.1}$Ag$_{0.1}$MnO$_3$ ($x = 0.1, 0.2, 0.3$) doped with both alkaline metal (Ag) and alkaline earth (Ca and Sr) elements are studied. The structural characterization of polycrystalline samples synthesized through low temperature nitrate route confirms orthorhombic structure for all the investigated samples. The morphology of crystal grains shows that the grains are nearly uniform in size and spherical. Electrical resistivity of samples reveal two transition peaks typical of Ag-doped lanthanum-basedmanganites. Significant room temperature magneto resistivity (MR) is observed for all the samples. MR is found to behave almost linearly with temperature for $x = 0.1$ sample for different magnetic field strengths in contrast to plateau type behaviour observed for $x = 0.3$ sample. Standard temperature-dependent resistivity models such as small polaron and variable range hopping are used to fit the resistivity data in the high temperature range. In the low temperature domain, the resistivity data could be fitted to a model which combines electron–electron scattering and weak localization.

【 授权许可】

CC BY