AES analysis of sodium in a corroded bioglass using a low-temperature technique

Measurements have been made of sodium compositional profiles at a glass surface using Auger electron spectroscopy. It has been found that stable sodium signals may be obtained by lowering the temperature of the glass to 80°K and by keeping the exciting electron beam current to less than 1 μA. Use of a low-energy electron flood gun had little effect on the AES measurement but was found to be valuable in reducing charging during ion bombardment of the low-temperature substrate. Observations on a glass designed for biological implant applications subjected to a simulated biological environment exposure showed that a region leached of alkali ions formed, and a Na-, Ca-, P-rich film built up on the surface.