Papers by Keyword: XPS Spectra

Abstract: Bulk Y₂NiMnO₆ samples were prepared by thermal decomposition technique at 800 °C for 6 hours. The effects of temperature on the structure of ceramics were investigated for different sintering temperatures in the range of 1000-1300 °C, while kept constant the sintering time of 12 hours. Structural characterization had been investigated via X-ray diffraction (XRD) on samples of different sintering temperatures. Results from the experiment had revealed that high temperature affected oxide in ceramic materials. Further analysis with X-ray photoelectron spectroscopy (XPS) technique had revealed an outstanding point of ceramics by investigating the Ni 2p, 2p_3/2, Mn 2p_1/2, 2p_3/2, and Y 3d_3/2, 3d_5/2 at the surface of Y₂NiMnO₆ ceramics. The changes in relative intensity of XPS peaks and the shifts in their binding energy (eV) were observed in the results, while the effect of temperature on oxide in ceramics may be investigated with dielectric property in the future.

Abstract: A compound as the lithium ion battery cathode materials were synthesized by high temperature solid phase synthesis method. The material is mainly the hexagonal structure and space group, and there is a little other phase. The XPS spectra display in the materials the Mn element existed by Mn4+ and the Ni element existed by the mix valent state between Ni2+ and Ni3+; the energy loss spectrum and ICP results are consistent, to ensure that the compounds is LiNi0.45Mn0.55O2 which we need; SEM figure shows it has a loose structure, particle size is about 0.2μm. At a current density 30mA/g at room temperature AC impedance analysis results show that an initial discharge capacity of 298 mAh/g ,which is higher than theoretical capacity of LiMnO2 285 mAh/g, that may be because of the synthesis LiNi0.45 Mn0.55 O2 is composite materials.After 13 circles it dropped to 93.2mAh/g and was steady, the efficiency reached 91.3%.

Abstract: Transparent conductive ZnGa₂O₄ thin films were prepared by magnetron sputtering. The chemical state of O, Zn and Ga in the deposited films was investigated by X-ray photoelectron spectroscopy (XPS), and the optical properties were characterized by optical transmittance spectra. The XPS studies reveal that no metallic Zn and Ga were detected in the ZnGa₂O₄ thin films, and Zn and Ga exist only in oxidized state. The optical bandgap was calculated by Tauc's theory and the optical constants were determined using Swanepoel's method. Furthermore, the dispersion behavior of the refractive index was studied by means of single-oscillator model, and the physical parameters and the refractive index dispersion parameter were obtained. The results provide some useful references for the potential application of the ZnGa₂O₄ thin films in optoelectronic devices.