Fluorescence Corrections in Thin-Film Texture Analysis

The pole-figure corrections in the case of fluorescent thin-film texture analysis using transmission and reflection techniques are detailed. No use of specific experimental fluorescence suppression is needed, as is proved for thin iron layers deposited on glass substrates.

An Ultra-Low-Temperature Diffractometer Based on an ³He–⁴He Dilution Refrigerator used for Synchrotron-Radiation X-ray Diffractometry and Topography

Synchrotron-radiation X-ray diffractometers used for crystalline materials and solid helium at ultra-low temperatures have been constructed with ³He-⁴He dilution refrigerators. By their use, the phase transitions of holmium elpasolite and solid ³He and ⁴He have been studied.

X-ray Analysis and Computer Modeling of the Structure of `Relaxor' Ferroelectrics Pb₃MgNb₂O₉ and Pb₂ScTaO₆ in the Paraelectric State

The random displacements of the Pb atom in `relaxor' ferroelectrics PMN and PST have been studied by X-ray diffraction and computer modeling.

Qu­antitative Phase Analysis using the Whole-Powder-Pattern Decomposition Method. I. Solution from Knowledge of Chemical Compositions

A new two-step procedure for quantitative phase analysis using the whole-powder-pattern decomposition method is proposed.

A Surface-Layer Texture Model for Correction of the Preferred-Orientation Effect

A model where texture is supposed to concentrate in a surface layer of the sample is presented and tested by measurement of X-ray intensities from ammonium chloride powder samples.

An Improved Method for the Normalization of the Scattered Intensity and Accurate Determination of the Macroscopic Density of Noncrystalline Materials

A procedure is presented that enables an estimation of the normalization constant with a high degree of accuracy.

The Post-Cotunnite Phase in BaCl₂, BaBr₂ and BaI₂ under High Pressure

X-ray powder diffraction patterns have been obtained for BaBr₂, BaCl₂ and BaI₂ as a function of pressure up to 40 GPa. All these cotunnite-structured compounds in ambient conditions transform to a monoclinic P112₁/a Z = 8 structure that is at the present time the final structure in the known high-pressure sequence of phase transformations in AX₂ compounds.

A Direct Determination of Micelle Structure from Small-Angle X-ray or Neutron Scattering Curves Measured by the Contrast-Variation Method

Micelle structure, on the basis of the two-shell model with ellipsoidal shape, can be directly analysed by the solution of simultaneous equations concerning the morphological parameters obtained from small-angle X-ray or neutron scattering curves.

Structure of the YBa₄Cu₂(CO₃)O_5.5±δ Oxycarbonate

This paper presents the crystal structure of YBa₄Cu₂(CO₃)O(_5.5±δ) determined by powder X-ray and neutron Rietveld refinement. Disordered (CO₃)²⁻ groups are found on two unique sites of a double perovskite cell.

High-Temperature Crystallographic Study of Mg-Doped TbAlO₃ and YAlO₃

Difference nuclear density maps Δρ, computed as Δρ(low temperature) - Δρ(high temperature) using only observed structure factors, show that thermal vibrations in Mg-doped TbAlO₃ and YAlO₃ are similar and that the difference density distribution for each atom can be described by zeroth-and second-order spherical harmonics (quadrupolar functions).

Determination of d_min and λ_min from the Intensity Distributions of Laue Patterns

The parameters d_min and λ_min, essential for the processing of Laue patterns, can be efficiently estimated by examination of the distribution of measured intensities as a function of d spacing and wavelength.

Absolute Lattice-Parameter Measurement

This method uses a high-resolution multiple-crystal multiple-reflection diffractometer to determine the interatomic spacings to within a few parts per million of homogeneous and inhomogeneous crystalline materials.

LQSWPF – a stand-alone full-matrix least-squares whole-pattern-fit program

The computer program LQSWPF is a full-matrix least-squares whole-pattern-fit program that can be used to extract the single line intensities from a powder diffraction pattern.

POLYNET – a teaching program for the plane crystallographic groups, for use on Apple Macintosh computers

A computer program is described that teaches about plane crystallographic groups by generating patterns plus an optional diagram of symmetries from a user-input asymmetric unit.

A program for sorting reflections for polycrystalline materials

A computer program that sorts X-ray reflections from polycrystalline materials by their crystallite of origin is described.

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