A new computer program for Rietveld analysis of X-ray powder diffraction patterns

Abstract

The Rietveld [J. Appl. Cryst. (1969), 2, 65-71] method of structure refinement from powder diffraction patterns is widely used with neutron data and increasingly so with X-ray data. A computer program for the application of the method with X-ray data, or with neutron nuclear scattering data, has been written ab initio in an effort to make it versatile, user oriented, portable, convenient, and largely self-contained yet reasonably comprehensive. It is of modular construction to facilitate user-desired modifications, one of which may be additions to the choice of four profile functions now included. The program accommodates either one or two wavelengths (e.g. c~1 and 0~ 2 or 2 and 2/2). It permits simultaneous refinement of the structures of two phases and the background. AbstractIntroduction A computer program has been written with the aim of calculating the domain of an atom in a structure. The domain may be limited by planes situated half-way between the atoms, or at a distance that takes into account the relative radii of the atoms. Data concerning this domain and the corresponding coordination polyhedron are computed and printed. Punched cards, to be used in a special plotting program, can also be produced. Three types of weighted coordination number are calculated.

The effect of grain size on electrical transport and magnetic properties of La0.9Te0.1MnO3

“…As it can be clearly seen from the inset of Fig.1, the grain size increases with increasing T s and the diffraction peak (0 2 4) shifts towards the lower angle from sample A to D, which is consistent with many results reported elsewhere [11,16]. The structural parameters of the samples are refined by the standard Rietveld technique [21] and the fitting between the experimental spectra and the calculated values is quite well based on the consideration of lower R P values as shown in Table 1. It shows that the lattice parameters of The magnetization as a function of the applied magnetic field at 5 K is shown in Fig.3.…”

Peculiarities of the martensitic transformation in ZrCu intermetallic compound - potential high temperature SMA

“…The internal friction g" 1 is calculated as Q~i =: k/(nf r ) with * the exponential decay parameter of the bending mode component [7]. Crystal structure analysis as performed using in situ high temperature X-ray diffractometry (Seifert 3003 TT, HDK 2.4 furnace, Cu-K<,) and Rietveld refinement (DBWS 9006PC program -new version [8]). Volume fractions of the observed phases were derived from the results of the Rietveld refinement according to [9].…”

Hydrothermal synthesis, characterization and Raman studies of Eu3+ activated Gd2O3 nanorods

“…The recorded powder XRD patterns were used to estimate the lattice parameters using the Fullproff program [10]. The surface morphology of the samples was studied using scanning electron microscopy (JEOL JSM 840A) by sputtering technique with gold as the covering contrast material.…”