X-ray Photoelectron Spectroscopy Analysis of Scandia-Ceria-Stabilized Zirconia Composites with Different Transport Properties

Abstract

This work aims to study a possible modification in the electronic structure of scandia-ceria-stabilized zirconia (10Sc1CeSZ) ceramics sintered at different temperatures. In addition to using X-ray diffraction (XRD), scanning electron microscopy (SEM) and impedance spectroscopy to investigate the structural and electrical properties, we employed X-ray photoelectron spectroscopy (XPS) to determine the chemical state information of the atoms involved, along with compositional analysis. As expected, a significant increase in grain ionic conductivity with the sintering temperature was present. This increase was accompanied by a decrease in the porosity of the samples, an increase in the grain size, and a transformation from the rhombohedral to the cubic phase. The phase transformation was detected not only using XRD, but also using XPS and, for this type of ceramic, XPS detected this transformation for the first time. In addition to the changes in the structural characteristics, the increase in the ionic conductivity was accompanied by a modification in the electronic structure of the ceramic surface. The XPS results showed that the surface of the ceramic sintered at the lower temperature of 1100 °C had a higher amount of Zr–OH bonds than the surface of the ceramic sintered at the higher temperature of 1400 °C. The existence of these Zr–OH bonds was confirmed using Fourier-transform infrared spectroscopy (FTIR). From this result, taken together with the difference between the oxygen/zirconium ratios in these ceramics, also identified using XPS, we conclude that there were fewer oxygen vacancies in the ceramic sintered at the lower temperature. It is argued that these two factors, together with the changes in the structural characteristics, have a direct influence on the conductive properties of the studied ceramics sintered at different temperatures.

The explanation of electrical properties changes under NH3 and H2 containing atmospheres in risen temperatures of ceria- and zirconia-based solid electrolytes by means of electrochemical impedance spectroscopy

“…The solution of this problem lies in additional material doping of small amounts of ceria (1 mol%) resulting in stabilization of the material cubic structure. A number of studies in the ternary system has been carried out so far [44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60].…”

Point Defects in Silicon-Doped β-Ga2O3: Hybrid-DFT Calculations

“…In this case, due to the ballistic nature of this process, the buildup of a lattice disorder occurs and it is accompanied by the formation of various types of defects in relatively large concentrations. Recent experimental studies of β-Ga 2 O 3 :Si system prepared by ion implantation with Si ions show that Si interstitials occur in large concentration but not as isolated atoms but as complexes of Si i with gallium and/or oxygen vacancies . Thus, to better understand the changes in the properties of β-Ga 2 O 3 and gallium oxide-based materials, the most favorable interstitial sites should be identified through further analysis and simulations.…”