Temperature-dependent X-ray Absorption Spectroscopy Research Articles

In-Situ Studies on Stoichiometry and Structure of Thin Film Yttria-Stabilized Zirconia under Thermal Processing

AbstractThin films of 8 mol% yttria-stabilized zirconia (YSZ) of thickness ranging from 15nm-500nm have been deposited on Si3N4(90nm)/Si substrates by RF sputtering at room temperature. These samples have been studied using in situ ion scattering techniques including Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA) to analyze the oxygen distribution and defect chemistry as a function of annealing in various oxidizing and reducing ambient upto 500°C. In addition, the structural quality of these films after long time annealing has been investigated using grazing incidence X-ray diffraction (GIXRD). Temperature dependent X-ray absorption spectroscopy (XAS) has been performed to study the unoccupied density of states and chemical nature of YSZ. In this paper, we will discuss in detail the effects of annealing in different ambient on the defect chemistry, structure and stability of films in these materials systems.

A new cell for temperature-dependent X-ray absorption spectroscopy of liquid solutions: application to PbBr2solutions in diethylene glycol

An in situ cell has been constructed for temperature-dependent X-ray absorption experiments (EXAFS and XANES) of lead bromine (PbBr2) solutions in diethylene glycol in the temperature range from room temperature up to about 433 K. The solution is kept in a thermostated container made of carbon-reinforced teflon between two thin chemically inert quartz glass windows with a high transmission for hard X-rays. The construction of the cell ensures that these X-ray windows are thermalized so that any possible precipitation of solid products from the solution is inhibited. The cell consists mainly of two hermetically sealed teflon containers for the thermostating fluid (silicon oil) that were fitted together in such a way that a small and variable volume (approximately 2-4 cm3) for the liquid under investigation was achieved. A small thermocouple in a glass enclosure was placed in the solution to maintain temperature control and feedback to the thermostat. The cell design and its performance for temperature-dependent in situ investigations with X-rays are reported. Some preliminary results obtained for PbBr2 solutions in diethylene glycol are given.

Temperature dependent EXAFS measurements on YGG during a sol-gel process

Temperature dependent X-ray absorption spectroscopy has been used as a local probe to elucidate the structure of yttrium gallium garnet produced by a sol-gel route. The treatment of our experimental data includes a cumulant expansion analysis taking into account the asymmetry of the pair distribution function resulting from disorder at high temperature.