The Initial Oxidation of HfNiSn Half-Heusler Alloy by Oxygen and Water Vapor.

The MNiSn (M = Ti, Zr, Hf) -type semiconductor half-Heusler alloys are leading candidates for the use as highly efficient waste heat recovery devices at elevated temperatures. For practical applications, it is crucial to consider also the environmental stability of the alloys at working conditions, and therefore it is required to characterize and understand their oxidation behavior. This work is focused on studying the surface composition and the initial oxidation of HfNiSn alloy by oxygen and water vapor at room temperature and at 1000 K by utilizing X-ray photoelectron spectroscopy.

The Initial Stage in Oxidation of ZrNiSn (Half Heusler) Alloy by Oxygen.

The MNiSn (M = Ti; Zr; Hf); half-Heusler semiconducting alloys have a high potential for use as -type thermoelectric materials at elevated temperatures (~1000 K). The alloys' durability is crucial for their commercial handling and use, and therefore it is required to characterize their surface oxidation behavior and stability at the working temperature. X-ray photoelectron spectroscopy was utilized to study the surface composition and oxidation of the ZrNiSn alloy at room and elevated temperatures.

Surface Oxidation of TiNiSn (Half-Heusler) Alloy by Oxygen and Water Vapor.

TiNiSn-based half-Heusler semiconducting compounds have the highest potential as -type thermoelectric materials for the use at elevated temperatures. In order to use these compounds in a thermoelectric module, it is crucial to examine their behaviour at a working temperature (approximately 1000 K) under oxygen and a humid atmosphere. Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) were utilized to study the surface composition and oxidation of the TiNiSn alloy at elevated temperatures.

Electron-induced interaction of selected hydrocarbons with TiO2 surfaces: the relevance to extreme ultraviolet lithography.

The aim of this work is to characterize desorption induced by electronic transition processes that affect the reflectivity of TiO2-capped multilayer mirrors used in extreme ultraviolet (EUV) lithography. A low energy electron beam is employed to mimic excitations initiated by EUV radiation. Temperature programmed desorption, x-ray photoelectron spectroscopy, and low energy ion scattering are used to analyze the surface reactions.

Monocular and binocular visual evoked potentials before and after cataract surgery.

Visual evoked cortical potentials (VEPs) were recorded from an individual with a mature cataract in one eye. Stimulation was both monocular and binocular and VEPs were obtained from three occipital scalp sites. Comparisons of recordings taken prior to cataract removal and after removal showed a dramatic increase in amplitude of potentials derived through stimulation of the affected eye.