THERMALLY-INDUCED STRUCTURAL MODIFICATION IN PT C X-RAY MULTILAYER MIRRORS FABRICATED BY ELECTRON-BEAM EVAPORATION/

Platinum-carbon multilayer mirrors with a bilayer spacing of 50 Angstr om were fabricated in an ultrahigh vacuum electron beam evaporator. Th e thermal stability of these multilayers was studied under vacuum anne aling using X-ray reflectivity and X-ray diffraction. Up to 450 degree s C, the bilayer spacing increases monotonically accompanied by a grad ual increase in crystallite size and grain texture. At 500 degrees C m ultilayer reflection vanishes, platinum crystallites grow abruptly, an d there is a strong texture of platinum in the [220] -plane. Possible reasons for thermally induced structural modifications in these multil ayers are discussed.