Observation of Phase change of X-ray Polarizability by Rocking Curves in the Bragg Case

Abstract

Rocking curves of the reflected and transmitted beams for GaAs 600 in the symmetric Bragg case were measured just below the K-absorption edge of Ga using X-rays from synchrotron radiation. Asymmetry and its reversal of the rocking curves for the transmitted beam were observed: the rocking-curve intensity in the lower-angle region of the exact Bragg angle was larger than that in the higher-angle region when the X-ray energy was 9 eV below the edge, while the asymmetry was reversed when the X-ray energy was about 6 eV below the edge. The reversal has been found to result from the change in the phase of X-ray polarizability.