Electrical and thermal properties of Pr0.6Sr0.4−xAgxMnO3 (x = 0.05 and 0.1) manganite

Abstract

Monovalent silver-doped Pr0.6Sr0.4−xAgxMnO3 manganite has been chosen for the electrical and thermal transport studies. The electrical measurements confirmed a metal–insulator transition around room temperature. For the analysis of the resistivity data, in the high-temperature paramagnetic region, the adiabatic small polaron hopping model was operative. The magnetoresistance studies, under different external magnetic field, showed that the MR peak is located at the metal–insulator transition and ferromagnetic–paramagnetic transition, which is characteristic for an intrinsic magnetoresistance. The thermal conductivity results exhibit a semicrystalline character with grain boundary scattering as a main mechanism limiting the heat transfer in samples. The electrical contribution to the thermal conductivity is relatively small, around 1%, as in most of the manganites. The transition point around room temperature is also visible. The additionally calculated thermal diffusivity parameter shows values of the order typically found in perovskites.