Solid-State Reaction of Nickel Thin Film Deposited on Titanium

Diffusion couples prepared by ion plating of 25 to 200nm thick Ni film onto tita-nium suhstrates have been annealed for up to 16h at 623～773K. The interdiffusion and the subsequent solid-state reaction behavior is investigated by X-rays using a Seeman-Bohlin diffractometer. The formation of an amorphous phase is observed upon thermal annealing over a temperature range of 643 to 773K. The formation of the intermetallic compounds of Ni3Ti and NiTi2 following the amorphous phase are also observed upon thermal annealing over temperature ranges of 658 to 688K for Ni3Ti and of 658 to 773K for NiTi2. Dataon relative integrated intensities of X-ray refl.ections are used to determine thethicknesses of these phases as a function of time， temperature， and de-posited Ni film thickness. In the case where the thickness of deposited Ni film is 100nm， the solid-state reaction proceeds most rapidly resulting in the formation of the thickest amorphous phase of 34nm upon thermal annealing for 1h at 678K