In this work we report the structural and electronic properties of the compound [Y0.8Ca0.2](Ba0.5Sr0.5)2Cu3O7-δ (YCaBaSr) which is a superconductor below the critical temperature TC = 80 K. This compound was prepared using the Sol-Gel method. The structural properties were studied by X-ray diffraction and electronic properties were studied by X-ray Photoemission Spectroscopy (XPS). The results were compared with those ones of the traditional superconductor YBa2Cu3O7-δ (YBCO). The X-ray photoemission spectra were taken at room temperature (normal state) and at 30 K (superconductor state). In the superconductor state, the X-ray photoemission spectra showed a shift in the O 1s. While the position of the Cu3p principal peaks do not change when measuring at 30 K. However, the spectra reveal the appearance of a new peak due to de hybridization of the Cu3d and O2p states. In addition, the Fou...

En este trabajo se reporta las propiedades estructurales y electrónicas del compuesto [Y0.8Ca0.2](Ba0.5Sr0.5)2Cu3O7-δ (YCaBaSr) que es superconductor con temperatura crítica TC = 80 K. El compuesto fue preparado mediante el método Sol-Gel. Las propiedades estructurales y electrónicas de este compuesto se estudiaron mediante difracción de rayos X (DRX) y espectroscopia de fotoemisión de rayos X (XPS) respectivamente. Los resultados fueron comparados con los del superconductor tradicional YBa2Cu3O7- δ (YBCO). Las medidas por XPS se realizaron a temperatura ambiente (en el estado normal) y a 30 K (estado superconductor). En el estado superconductor, los espectros XPS de ambos compuestos muestran corrimiento en el pico O 1s. Mientras que, la posición de los picos principales del Cu 3p no cambian de posición al ser medidos a 30 K y 293 K. Sin embargo, se observa en el espectro la ap...

Bare maghemite nanoparticles (Nps), binary, and ternary magnetic nanocomposites made with titanium dioxide (TiO2) and graphene oxide (GO) were synthesized by a facile and cheap coprecipitation chemical route, and used as magnetic nanoadsorbents to remove arsenite (As(III)) and arsenate (As(V)) from water. The structural, morphological, magnetic and surface properties were analyzed by XRD, TEM microscopy, FTIR and Raman vibrational spectroscopy, Mössbauer technique and N2 adsorption-desorption measurements. It was found that materials were composed of maghemite nanoparticles with crystallites diameters varying from 9 to 13 nm for bare Nps, binary and ternary nanocomposites, with these nanocomposites having a high percentage of maghemite phase (80%). The presence of TiO2 and GO in the binary and ternary materials was also confirmed. All the samples were found to show magnetic properties a...