Observation of polymer alloy by spectral soft X-ray microscopy with a laser plasma X-ray source

A polymer alloy film on a photographic plate (ILFORD, Q-plate) was exposed to the dispersed soft X-rays in the wavelength region between 8.1 nm and 33.6 nm. The image on Q-plate was magnified by an optical microscope. In the microscopic images of the polymer alloy containing silicon, circular spots of about 30 μm in diameter scattered in a matrix was observed with certain wavelengths of soft X-rays. The image contrast between the spots and the matrix was reversed at around the wavelengths of 12.6 nm and 17.5 nm. This reversal of contrast suggests that these circular spots, or islands, are silicon-rich phases because the L-absorption edge of silicon is 12.3 nm.