Study of Electrical Properties and Conduction Mechanisms in La0.4Bi0.3Sr0.2Ba0.1MnO3 Ceramic Elaborated by Sol Gel Method

Using the sol gel method, we will incorporate Bi, Sr and Ba in site A into the LaMnO3 matrix to get La0.4Bi0.3Sr0.2Ba0.1MnO3 compound. Our aim is to explore the structural and the electrical properties of this compound. X-ray diffraction study indicates that the investigated compound exhibits a rhombohedral crystalline phase with R3̅c space symmetry. Temperature dependence of the electrical conductivity indicates that the investigated sample exhibits a semiconductor behavior in the explored temperature range [80–400 K]. Then a saturation region appears at ambient temperature. For ac-conductivity, the spectra obey to the double Jonscher response in the temperature range [80–135 K], the single Jonscher power law for [140–210 K] and to the classical Drude model for [220–400 K]. At elevated temperatures, the conduction is governed by the thermally activated hopping of small polaron (SPH). However, the most appropriate conduction mechanism at low temperatures is the Variable Range Hopping process (VRH). In the intermediate temperature range, the transport properties are described by Greaves variable range hopping model. Then, the correlated barrier hopping (CBH) and the Jump relaxation Model (JRM) were used to explain the dispersion region. Moreover, the value of the extracted activation energies is strongly dependent on frequency suggesting that the hopping mechanism is the dominant conduction process. Also, the disorder energy decreases with increasing frequency indicating that the separation path between jump centers is modified. Indeed, the contribution of various processes to the conductivity makes our system as good candidate in the solid oxide fuel cells (SOFCs) applications.