Metastable phase equilibrium during solid-state amorphization reaction of Zr-Co layers

Abstract

The crystal-glass transition of Co-Zr layers via interdiffusion has been followed by Rutherford-backscattering spectrometry and x-ray-diffraction analysis. Thin-film multilayer samples of Co and Zr were annealed at 250 \ifmmode^\circ\else\textdegree\fi{}C for different times up to 21 h. Planar growth of the amorphous layer is observed. The changes in the concentration profiles, as observed with Rutherford-backscattering spectrometry, in combination with corresponding x-ray analysis, indicate an interstitial solid solution of \ensuremath{\approxeq}3 at. % Co in crystalline Zr probably preceding the glass transition. This effect is discussed in the context of a metastable phase diagram.