The Historical Development of X-ray Absorption Fine Spectroscopy and of Its Applications to Materials Science

This essay sketches the development of X-ray Absorption Fine Spectroscopy (XAFS) ever since the second half of the twentieth century. At that time, synchrotrons started competing with X-ray discharge tubes as the sources of the excitation able to show the pre- and near-edge structures (XANES) and extended oscillations (EXAFS) that characterize the X-ray absorption edge of solid matter. Actually, modern XAFS began to be used after 1975, when the hard-X-ray synchrotron radiation derived from storage rings took over. Ever since, XAFS have greatly contributed to both technical refinement and to theoretical development of Materials Science. Although a unified theory of X-ray fine absorption has not been reached yet, many XAFS advancements benefited from theoretical models and complex calculations made possible by continuous growth of computing power, while contributing to developing new or previously never used materials.