Structure of inorganic nanoclusters embedded in solid matrixes: an X-ray absorption study

Results of X-ray absorption studies of copper nanoclusters embedded in SiO₂ matrix and selenium chains confined in channels of cancrinite are reported. Initially randomly distributed copper atoms mainly surrounded by silicon species in an as-made film upon annealing form copper nanoclusters with a characteristic size of 80 Å and the structure identical to that of bulk copper. The characteristic size of the clusters does not increase with further annealing. Selenium in cancrinite is shown to form strongly oriented linear dimerised chains with a bond length much larger than that in bulk forms of selenium.