The microwave-assisted hydrothermal method was used to obtain α-Ag2WO4. Rietveld refinement confirmed that α-Ag2WO4 is stable in the orthorhombic phase, without secondary phase. However, field-effect scanning electron microscope analysis showed that α-Ag2WO4 nanorods surfaces contain silver nanoparticles, confirmed by the X-ray photoelectron spectroscopy by the peak observed at 374.39 eV. In addition to metallic Ag, other Ag oxidation states were also observed on the surface. Hence, Ag (I) as Ag2O and Ag (I) as Ag2WO4 also were identified. DC measurements exhibited a high capacity of charge storage, nevertheless, with a large loss tangent (0.12 µC.cm-2.V-1) and no residual polarization for the voltage range between -100 V and +100 V. AC measurements at frequencies less than 275 Hz, revealed that ionic polarization is dominant, whereas at frequencies higher than 275 Hz, the electronic behavior predominates. The potential of electromagnetic energy conversion in thermal was observed from loss tangent analysis.

A systematic study about synthesis of In1-xSnxO2 (ITO) nanostructured crystals by microwave-assisted solvothermal method is reported. Different solutions using InCl3.4H2O and SnCl4.5H2O precursors in ethylene glycol solvent were prepared in distinct pHs (acid and basic ones). The syntheses were performed at 200 ºC using a heating rate of 50 ºC min-1 and soaking time of 30 minutes. All the synthesized powders were characterized by X-ray Diffraction (XRD) and Rietveld refinement to study the phase evolution as a function of pH. The materials synthesized in the pH ranging between 11.5 and 11.9 were further studied by field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) techniques. As ITO materials have many practical applications due to their transparency in the visible spectrum, UV-Vis spectroscopy analysis was performed to obtain the optical band gap and the respective optical window.