The Influence of Ti Doping at the Mn Site on Magnetoresistance and Thermopower Properties of Nd$_{0.5}$Ca$_{0.5}$MnO$_3$

Nd-Ca-based manganite Nd$_{0.5}$Ca$_{0.5}$MnO$_3$ and 10% Ti-doped manganite Nd$_{0.5}$Ca$_{0.5}$MnO$_3$ denoted by N and N$_{0.1}$, respectively, were prepared using solid-state reaction method. Resistivity gets increased for the Ti-doped sample. The parent compound N has remarkably high magnetoresistance. The highest value of Seebeck coefficient for N is -97 $\mu$VK$^{-1}$ at 143 K and for N$_{0.1}$ is -207 $\mu$VK$^{-1}$ at 203 K. Variable range hopping mechanism successfully explains the high temperature resistivity and thermopower data.