OBSERVATIONS OF AN UNUSUAL MODULATED STRUCTURE WITH DOUBLE-PERIODICITY IN FE-AL MULTILAYERS

We report the observation of an unusual modulated structure with doubl e-periodicity in the vapour deposited Fe-Al multilayers by X-ray diffr action analysis. Such structure appeared when the Fe layer thickness w as between 2 and 6 nm with a fixed Al layer thickness of 8.5 nm. The d iffraction analysis also revealed an alternative Al texture orientatio ns associated with the double-periodicity. The alternative texture cau sed some difference in the Fe and Al layer density and might play a ro le in forming the double-periodicity, however, the major physical issu es responsible for the unusual observations are still unclear and need further studies. (C) 1997 Elsevier Science S.A.