NMR of Single Crystal Surfaces

Purdue University, West Lafayette IN

Investigators

Abstract

Professor Michael D. Raftery is supported by the Experimental Physical Chemistry Program for his research on NMR of single crystal surfaces. Xenon optical pumping and magic angle spinning solid-state NMR will be combined to produce unique, surface specific studies (OPMAS). Powder semiconductor surfaces passivated with organic functional groups will be studied to examine bond coordination, surface heterogeneity and surface oxidation processes. Extensions to surfaces of crystalline silicon and germanium wafers will be attempted. Experiments for measuring chemical shifts as a function of depth in diamond and group IV materials will also be performed. Techniques for improving polarization transfer from optically polarized xenon to surface nuclei will be developed. Surface phenomena have been traditionally difficult to study, and the addition of NMR to the battery of surface sensitive methods would be a large advance with possible biological and even medical outcomes. This application, hydrocarbons on silicon, is important in the semiconductor industry.