Structure, transport and magnetic properties of electron-doped perovskites R_xCa_1-xMnO₃ (R = La, y and Ce)

In this study, the transport and magnetic properties of electron-doped perovskites R_xCa_1-xMnO₃ (R = La, Y and Ce) were investigated. As the R ion content increases, the crystal structure, resistivity, magnetoresistance, magnetization and related characteristic temperature of these systems all vary systematically. The data show that the variations in the electrical transport properties are mainly dependent on carrier concentration, whereas the magnetic properties of these systems are also dependent on crystal structure. When the carrier concentration exceeds a certain level, charge ordering occurs, leading to the localized electronic state and peaks in the magnetization curves. The magnetic transition temperature T_N can be well described by crystal structural parameters, suggesting that crystal structure and magnetic properties are strongly coupled to each other.