Effect of elastic stresses on solid-state amorphization of Zr/Co multilayers

We have examined the effect of externally applied stresses on the solid-sta te amorphization reaction of Zr/Co multilayers prepared by electron-beam ev aporation. Three identically deposited samples were attached onto a three-p oint bending apparatus to impose different elastic strains on individual sa mples and subsequently annealed at temperatures of 483, 503 and 543 K. The imposed bending strain, estimated to be as small as 0.08%, had a significan t influence on the amorphization kinetics. Cross-sectional transmission ele ctron microscopy revealed clearly that changing the applied bending strain from tensile to compressive enhanced the amorphization reaction. This enhan cement was accompanied by an extensive amorphization along grain boundaries in the Zr layers. According to the present observations, it is suggested t hat the applied bending stresses play an important role in the amorphizatio n reaction by influencing the interface reaction barrier associated with th e actual transformation of the terminal solution phase of Zr into the amorp hous ph (a) over tilde se. (C) 2000 Elsevier Science B.V. All rights reserv ed.