Читать книгу Materials for Biomedical Engineering - Mohamed N. Rahaman - Страница 173

SIMS consists of bombarding a surface with a primary beam of Ar, Ne, or He ions and analyzing the emitted ions and ion clusters in a mass spectrometer. As the emitted ions and ion clusters are characteristic of the surface, SIMS provides information about the chemical composition of the surface. Some information on the chemical bonding of the atoms can also be extracted by analyzing the composition of emitted ions and ion clusters.

SIMS can be used in two distinct modes of analysis. In static SIMS, an ion beam of low intensity is used so that analysis is confined to the outermost layers of the surface. In comparison, in dynamic SIMS, a high intensity beam is used to erode successive atomic layers at a relatively rapid rate. Static SIMS is more relevant to the application of biomaterials as it provides information about the outermost surface atoms. While SIMS has the advantages of high spatial resolution, high sensitivity for qualitative elemental analysis and the ability to provide a detailed analysis of the chemical composition of the surface, quantitative analysis of the surface composition is often difficult.