The measurement of anomalous scattering near the Ga K absorption edge in GaP

By the use of an SSD diffractometer and continuous X-rays, the energy dependences of Δf' and Δf” values of Ga have been studied on GaP with energy resolution of about several eV around the Ga K edge; the values of Δf” were determined by the measurement of the absorption coefficient, and then the values of Δf' have been obtained from the precisely measured ratio of Friedel-pair reflexions from a (111) single-crystal plate of polar GaP. Fine structures have been found in Δf” and therefore in Δf' corresponding to those of the absorption coefficient. The present work has shown that the measured values of Δf' more or less reasonably agree with the curves calculated from the dispersion relation.