SUBSTANTIAL DIFFUSION OF ZR DURING SOLID-STATE AMORPHIZATION IN NI ZRMULTILAYERS/

To examine the proposed model that amorphization is achieved by the mo tion of one species only, Ni/Zr multilayers have been prepared by sput ter deposition at a pressure of 1 Pa. The as-deposited specimen shows the planar and sharp interface between Ni and Zr layers. The amorphous phase is clearly observed at the residual Ni layers and around the vo id edge in the Zr layer from the cross-sectional TEM images of the sam ples annealed at 300 degrees C for 1 h. Composition analysis verifies that considerable Zr diffusion occurs through the grain boundary in th e Ni layer during the annealing. The activation energy for amorphizati on is determined to be 1.17 eV per atom through a Kissinger-type analy sis. This paper clearly shows the formation of amorphous NiZr alloys w hen Zr diffusion is comparable to Ni diffusion.