MULTILAYERS - A WAY TO PREPARE METASTABLE PHASES BY MULTIPLE INTERFACE REACTIONS

Experiments on interface reactions occurring even at low temperatures (e.g. 77 K) and resulting in metastable amorphous layers restricted to a small depth of typically 3 nm are reviewed. This phenomenon can be exploited to prepare thick amorphous films by stacking bilayers with a modulation length smaller than the reaction depth. With emphasis on t he In/Pd system, additional experimental results are provided on the l ong-range diffusion as well as on the reaction behaviour on single-cry stalline substrates. For this latter point, a combination of Auger and electron energy loss spectroscopy has been applied. The results indic ate a clear difference to systems exhibiting a solid-state amorphisati on reaction like Zr/Co.