METAL AL2O3 - A NEW CLASS OF X-RAY MIRRORS

We have examined sputtered metal/Al2O3 multilayers (metal: Co, Pt, W) with respect to their suitability as x-ray mirrors in high temperature environments. The rf-sputtering technique leads to layered structures with interface roughnesses of only 0.2 nm as confirmed by x-ray scatt ering and transmission electron microscopy. In situ resistance measure ments characterize the percolation process and indicate the lower thic kness limits for the chosen materials which lead to minimum modulation periods of approximate to 2 nm. The samples were characterized after stepwise annealing up to 1000 degrees C. Reflectivity values of nearly 100% at the first satellite-reflection were found in the case of Pt a nd W (for lambda = 0.15418 nm). The most stable W/Al2O3 multilayer ref lects 70% of the primary beam even after annealing at 900 degrees C. ( C) 1996 American Institute of Physics.