Electrical transport properties of La0.67(Sr1-xBax)0.33Mn0.9Ti0.1O3 perovskite manganite

Influence of Ba doping on the structure and electrical transport properties of polycrystalline La0.67(Sr1-xBax)0.33Mn0.9Ti0.1O3 (0 ? x ? 1.00) perovskite manganites were studied. The samples synthesized by solid-state reaction method experience a transformation from R-3C rhombohedral to Pm3m cubic structure with the increment of Ba concentration. Temperature dependent resistivity showed that the metal-insulator transition temperature decreases from 117 K to 60 K with increasing Ba content up to x = 0.75. The low temperature resistivity below the metal-insulator transition temperature, Tp was well fitted with the ? = ?o + ?2T 2 equation indicating the contribution of domain or grain boundary mechanisms and the electron-electron scattering mechanism in the conduction. Contrary to that, in the high temperature insulating regime (T > Tp), the resistivity follows variable range hopping (VRH) and small polaron hopping (SPH) conduction mechanisms