Transport properties of La0.9Sr0.1MnO3 manganite

Impedance spectroscopy technique was used to characterize the electrical properties in a wide range of frequency [40-10(5) Hz] and temperature [80-700 K]. As a result, AC-conductivity spectrum follows the 'double Jonscher Power Law' in the temperature range [80-280 K], 'Jonscher Power Law' in [300-600 K] range and at 700 Kit is described by the classical Drude model. Moreover, the AC-conductivity analysis reveals the contribution of multiple mechanisms in conduction. In fact, the variation of the frequency exponent 's(1)' with temperature shows that the correlated barrier hopping mechanism is the dominated model for conduction of charge carriers beyond T = 470 K. The previous model was observed again according to the temperature dependence of the frequency exponent 's(2).' Then, the deduced activation energy decreases with increasing frequency suggesting the availability of hopping conduction. The temperature dependence of AC-conductivity proves the existence of metal semi-conductor transition at 200 K. At high temperatures, the DC-conductivity analysis reveals that the conduction process is dominated by thermally activated hopping of small polaron. However, at low temperatures, it is confirmed that the most suitable mechanism for conduction is the Shklovskii-Efros-Variable Range Hopping process.