Anomalous grazing X-ray reflectometry for determining the number density of atoms in the near-surface region

A new method has been proposed for determining the atomic number density of a near-surface element in materials using its grazing X-ray reflection and anomalous dispersion effect. The essential equations for analyzing the measured intensity data and the capability of this anomalous grazing X-ray reflection (AGXR) method have been described by obtaining the atomic number densities of near surface elements in some selected examples of ZrO2-Y2O3 crystal, Cr thin film grown on a glass substrate and passivated stainless steel. The variation of the critical angles of total external reflection through the anomalous dispersion effect was clearly detected and the results suggest the AGXR method is rather surprisingly works well, although there are differences in detail when compared with the values calculated from the bulk density. (author)