Transformative Effect of Oxygen Plasma to Upshot the Structural and Electrical Properties of Pr0.5Sr0.5MnO3 Manganites

A methodical inquiry of the outcome of oxygen plasma exposure in low bandwidth compounds belonging to the perovskite family Pr1-xSrxMnO3 manganites where x = 0.5, has been presented in this communication by comparing the structural and transport properties of the untreated and plasma treated samples. It is witnessed that the high-temperature transmission is carried out by small polarons while the low-temperature transmission is attributed to variable range polarons. The changes in the transport properties may be attributed to the structural modification due to plasma exposure as revealed by the Rietveld analysis of the X-ray diffraction pattern. Further, oxygen plasma exposure boosts the conductivity due to the integration of oxygen ions in the plasma-exposed samples, thereby rendering them oxygen-rich.Comment: 21 pages, 9 Figures, 3 Table

Investigation of Electrical and Thermoelectric Properties of ZnO/rGO Composites Prepared by Conventional Solid-state Reaction Method

ZnO/rGO composites are prepared by the conventional solid-state reaction method. Structural properties of prepared compounds were studied using XRD technique and it is observed that all the samples are crystallized in wurtzite structure. Electrical resistivity measurements were carried out using four probe method employing a closed cycle refrigerator. With addition of rGO, colossal reduction in the resistivity is observed which is about three orders of magnitude smaller than that of the pure sample of ZnO. Room temperature Hall measurements were performed to estimate the bulk concentration and results show that addition of rGO into ZnO matrix enhances the number of charge carriers. Thermopower measurements were carried out using differential dc method and a large reduction in Seebeck coefficient is observed