Order in CdS nanoparticles in glass

We have employed X-ray absorption spectroscopy to study the local bonding of Cd atoms in borosilicate glasses doped with Cd and S after heat treatment at temperatures from 550 to 750°C. Varying temperature and time can form CdS particles with average size from a few to several nanometers. In crystals grown below ∼700°C, the apparent number of second neighbors found from analysis of X-ray absorption fine structure is only a small fraction of that expected for well-ordered crystallites of these sizes. We attribute this apparent coordination deficit to substantial short-range structural disorder.