TEM analysis of Co–Gd and Co–Gd multilayer structures

Sputter-deposited Co–Gd and Cr–Gd multilayer films were studied by high resolution transmission electron microscopy (HRTEM). These two systems are expected to give rise to quite different structures. In good agreement with predictions, the individual Cr and Gd layers were found to be 100% crystalline with sharp interfaces and no noticeable intermixing. Conversely, the Co–Gd multilayer system underwent a solid state amorphization reaction during the deposition itself. This reaction has been found elsewhere to show an asymmetric character with the order of deposition, strong evidence for which is observed in this work.