XRLINE, A PROGRAM TO EVALUATE THE CRYSTALLITE SIZE OF SUPPORTED METAL-CATALYSTS BY SINGLE X-RAY PROFILE FOURIER-ANALYSIS

The computer program presented is based on the Fourier analysis of a single X-ray diffraction profile. An X-ray diffraction method is presented which is capable of determining the average particle size, microstrain, stacking fault probability as well as the particle size distribution function in crystalline materials. The main numerical methods used are: 1. (i) smoothing and interpolation by 3rd-order piecewice polynomial functions or by cubic splines with the least squares method; 2. (ii) numerical integration by successive five points formulae and numerical derivative by cubic splines with the least squares method; 3. (iii) estimation of parameters by the weighted least squares method. The results for supported platinum catalysts used in teh H/D isotopic exchange reaction are illustrated. © 1990.