The Influence of Ti Doping at the Mn Site on Magnetoresistance and Thermopower Properties of Sm0.6Sr0.4MnO3

The influence of non-magnetic Ti doping at the Mn site on magnetoresistance and thermopower properties of Sm0.6Sr0.4MnO3 (Sm0.6Sr0.4Mn1-xTixO3, x = 0, 0.1 and 0.15 denoted by SMO, STMO0.1 and STMO0.15 respectively) prepared by solid-state reaction method is investigated. All three samples exhibit metal–insulator transition. STMO0.15 has a sudden drop of resistivity around 100 K. At low temperatures, the magnetoresistances of the samples get increased with Ti doping. All samples have negative thermoelectric power (TEP) at room temperature. Both high-temperature resistivity and TEP of the samples are successfully analyzed using the Variable Range hopping (VRH) model. Power factor, which determines the quality of a TEP material, is comparatively high for 15% Ti-doped sample STMO0.15 at room temperature.