Structural, electrical, dielectric properties and conduction mechanism of sol-gel prepared Pr0.75Bi0.05Sr0.1Ba0.1Mn0.98Ti0.02O3 compound

摘要： A detailed investigation of structural, electrical and dielectric properties of Pr0.75Bi0.05Sr0.1Ba0.1Mn0.98Ti0.02O3 manganite prepared by the sol-gel method was undertaken. The Rietveld refinement of X-ray diffraction pattern reveals that this compound is indexed in the orthorhombic structure with Pbnm space group. Structural properties are also analyzed by scanning electron microscopy and energy dispersive X-ray spectroscopy at room temperature. DC conductivity (σDC) data show the presence of a semiconductor-metal transition at TSM=360K. σDC is described by small polaron hopping model at high temperatures and variable range hopping model at low temperatures. AC conductivity results follow the universal Jonscher's power law at relatively low temperatures and Drude's model at high temperatures. The impedance plots display the contribution of both intra- and inter-granular contributions. Dielectric measurements exhibit highly remarkable dielectric permittivities useful in electronic devices. Dielectric losses are shown to be governed by the DC conduction mechanism and described by the Giuntini theory.