PRESSURE-DEPENDENT HYDROGEN DIFFUSION IN THE INTERMETALLIC COMPOUND FE0.5TI0.5

The Green's function technique is used in the scattering matrix formal ism to compute the mean square displacement (MSD) of hydrogen intersti tials and the reaction coordinate technique is used to calculate the h ydrogen diffusion parameters in the intermetallic compound Fe0.5Ti0.5 from normal pressure to 2.5 GPa pressure for low concentration of hydr ogen. The MSD of the metal atoms surrounding the interstitial are foun d to be smaller than those of the host crystal in agreement with NbH(x ). The diffusion of hydrogen into the alloy is found to decrease with increase in pressure as experimentally observed in PdH(x).