On using a Philips x-ray powder diffractometer for x-ray reflectivity

Abstract

This paper discusses the use of a Philips x-ray powder diffractometer (XRD) for x-ray reflectometry. This involves the precise alignment of the incident beam with the sample surface at grazing incidence. Two factors have to be taken into account, small spatial displacement of the beam and angular deviation of the sample surface. The beam was aligned at 2° 2θ by setting the beam at the center of the sample surface to eliminate spatial displacement. The beam was then aligned at grazing incidence by adjustment of the sample stage knob to eliminate angular deviation. The reflectivity curves of a gold-protected mirror, BK7 and borofloat windows were recorded. The critical angle, density and dispersion of the samples were derived from the recorded intensities.