Image plate X-ray diffraction and X-ray reflectivity characterization of protective coatings and thin films

Two-dimensional image plate applications in X-ray diffraction (XRD) and X-r ay reflectivity (XRR) characterization, using a grazing incidence geometry and radiation from a conventional X-ray tube, were explored. XRD and XRR da ta obtained from a conventional diffractometer using a Si (Li) detector com plement image plate results to give more complete phase and structure infor mation. Protective chromium coatings, electrochemically deposited onto the bore of steel cylinders, were investigated. Retained austenite content in m artinsitic steel was measured in simulated, inside-diameter, bore geometry. This approach demonstrates the versatility of the method for non-destructi ve chemical analysis and phase differentiation of interior bore surfaces in piping structures. MATLAB-based processing software was developed to facil itate quantitative image analysis, including multiple 2 theta scans, chi -p lots, and pole figure re-construction from multiple-phi images, where chi a nd phi designate, respectively, specimen tilt and rotation. For XRR applica tions, a 12-nm tantalum and an 82-nm tantalum oxide thin film sputtered on (100)-oriented silicon wafers were investigated. Density and thin him thick ness were obtained from specular reflectivity modeling involving the period icity of the interference fringes. Two-dimensional Kiessig interference-fri nge images were analyzed and compared with conventional specular XRR for th e measurement of thin film thickness and thickness uniformity over a sample . (C) 2000 Elsevier Science B.V. All rights reserved.