New diffraction technique may improve understanding of mineral surfaces

Abstract

Measurement of the photoelectron diffraction patterns of all major constituents of mineral surfaces by means of X ray photoelectron diffraction (XPD), a new and largely undeveloped technique, may lead to a much better understanding of those surfaces, research suggests [Fadley, 1992; Chambers, 1992; Osterwald et al., 1995; Fadley et al., 1997]. The technique allows scientists to characterize clean surfaces of minerals and investigate interactions between such surfaces and gases, liquids, and solids. It also promises accurate three‐dimensional imaging of the atomic environment around each type of atom near a mineral surface. In a specific experiment, the X ray photoelectron diffraction (XPD) patterns were measured for all major chemical constituents of a clean phlogopite (001) surface prepared in ultrahigh vacuum. Such patterns have been shown to provide direct and unique information, at the atomic scale, of the location and local bonding geometry for each element in the mineral surface.