Substrate material for X-ray optical components

摘要

There is provided a substrate material for an optical component for X-rays of wavelength lambdaR. The substrate includes (a) a glass phase made of amorphous material having a positive coefficient of thermal expansion, and (b) a crystal phase including microcrystallites having a negative coefficient of thermal expansion and a mean size of less than about 4 lambdaR. The substrate material has a stoichiometric ratio of the crystal phase to the glass phase such that a coefficient of thermal expansion of the substrate material is less than about 5x10<-6 >K<-1 >in a temperature range of about 20° C. to 100° C. The substrate material, following a surface treatment, has a high spatial frequency roughness (HSFR) of less than about lambdaR/30 rms.