Bragg-Brentano and Seeman-Bohlin Diffractometers for Thin Films

Abstract

AbstractThe performances of Seeman-Bohlin (S-B) and Bragg-Brentano (B-B) diffractometers with flat thin film samples were compared on the basis of equal instrumental aberrations. It was found that the S-B arrangement has only a marginal advantage as regards diffracted intensity, and that both types of diffractometer may be successfully employed for characterization of thin films. Diffraction data obtained with very thin metallic films (down to 30 Å) are included for illustration. In order to eliminate reflections from the singlecrystal substrate in the B-B diffractometer, sample tilting was employed. Provided the tilting angle remains within 0.5°, sample tilting causes only moderate additional broadening of the thin film peaks.