X-ray Absorption Spectroscopy

This chapter reviews recent progress in applications of X-ray absorption spectroscopy to the study of clays and clay minerals. Scanning transmission X-ray microscopy (STXM) has been shown to be a versatile tool, useful for the study of cation exchange in smectite, dissolution reactions in wet samples and to determine the amount of tetrahedral Fe in biogenic iron oxides. STXM image analysis lends itself well to statistical analyses developed in the biological sciences. Other soft and hard X-ray absorption spectroscopies have continued to play important roles in quantifying the relative proportions of cation coordination and oxidation state in oxides, smectites and other layered minerals.