A study on the thermopower and resistivity properties of Ti doped manganites Gd0.7Sr0.3Mn1-xTixO3 (x = 0,0.1 and 0.15)

Abstract Thermoelectric power (TEP) along with temperature dependent resistivity of Ti doped Gd-Sr manganite (Gd0.7Sr0.3Mn1-xTixO3 (x = 0, 0.1 and 0.15) denoted by G, G0.1 and G0.15 respectively) are studied systematically. Significant Seebeck coefficients (S) are exhibited by all the three samples which is a most desirable quality of a good thermoelectric material. In the case of sample G, highest attained value of S is −35.57mVK−1 at 91 K. For G0.1 and G0.15 highest attained values are −31.60 mVK−1 at 114 K and –33.76 mVK−1 at 133 K respectively. This reveals that Ti doping shifts the highest value of S to higher temperatures. Diffusion and magnon drag contribute to TEP at lower temperatures. Temperature dependence of thermopower at comparatively higher temperature region gives an insight of combined SPH and VRH models. Temperature dependent electrical resistivity is successfully analyzed within the interesting framework of variable range hopping of small polarons.