Thermal desorption of Ti-Mo alloy deuterides

The desorption kinetics of TiMox alloy deuterides with different Mo contents (x= 0.03,0.13,0.25,0.50,1.00, atomic ratio) were studied in an ultra-high vacuum system by applying the constant volume method. The rate constant of desorption kd, is calculated by first-order rate analysis, and the desorption activation energy Ed is obtained from the relationship lnkd vs 1000/T. To investigate the kinetic isotope effect of Ti-Mo alloy hydrides, Ed of the deuterides is compared with that of the protides. When x=0.03, Ed of deuterium desorption is larger than that of protium desorption. When x=0.13 and 0.25, Ed of protium desorption is larger than that of deuterium desorption.When x=0.50,1.00, the kinetic isotope effect is not obvious.The nature of the kinetic isotope effect is discussed by the stability of deuterides and hydrides at various temperatures. (authors)