Thermal desorption of hydrogen at the titanium hydride-oxide interface

Changes in hydrogen distribution in delta-phase titanium hydrides (TiH1.92 similar to 1.95), covered with titanium oxide layers (TiO and TiO2), were investigated by elastic recoil detection analysis (ERDA) after isochronal and isothermal annealing experiments. The hydrogen concentration near to the surface of the hydride exponentially decreased as a function of annealing time in the temperature range front 423 to 523 K. The result shows that the thermal desorption of hydrogen from the hydride is governed by first-order reaction kinetics and greatly depends on the thermal detrapping process. The thermal detrapping rates of hydrogen at the hydride-oxide interface were estimated and their activation energy was determined to be 1.3 +/- 0.2 eV.