Lattice and grain boundary diffusion of oxygen in titanium subhydride studied by Auger sputter profiling

Abstract

AbstractAnodic TiO2 films were grown on titanium subhydride samples under galvanostatic conditions. The samples were heat treated at temperatures between 550 and 600°C and changes in the profile of oxygen concentration as a function of depth were monitored using Auger electron spectroscopy (AES). For TiH0.87 and TiH0.96 at 600°C, the lattice oxygen diffusivity, D1 is ∼5 × 10−15 cm2 s−1 and the grain boundary oxygen diffusivity, Db, is given by δDb ∼3 × 10−18 cm3 s−1 where δ is the grain boundary width in centimeters. Using electron energy loss spectroscopy (EELS) to measure the bulk plasmon loss energy it was possible to determine the stoichiometry of the titanium subhydride substrate. Samples of TiH0.87 foil were found to dehydride somewhat upon heating to 600°C.