A new and improved sample holder suited for small samples has been developed for X-ray diffractometry. This holder is made from a commercial semiconductor grade of silicon wafer grown and cut along the [100]-axis, i.e., Si(100). This new holder not only meets almost all basic requirements of an ideal holder, namely, flat and damage free surface, low background noise, few interference peaks, and desired shape with different cavity sizes, but also provides additional advantages for measuring crystallite sizes and mass absorption coefficients. Furthermore, this holder is easy to clean and has good appearance because of its polished surface. A U.S. patent has been issued and a commercialization effort is underway.

Two new thiophosphates with an original structure corresponding to formula ATi2(PS4)3 (with A=Na,Ag) were synthesized by solid-state reaction. The two compounds are isostructural, hexagonal space group P6cc, Z=8. A single crystal of NaTi2(PS4)3 has been studied. Unit-cell parameters were determined for NaTi2(PS4)3 and AgTi2(PS4)3, respectively: a= 19.9131(6) Å, c= 11.5542(7) Å, V=3967.8(3) Å3 and a=20.0146(8) Å, c= 11.5467(8) Å, V=4005.7(4) Å3. Powder diffraction data are reported.

X-ray powder diffraction data are reported for the monohydrated ammonium dioxalatotitanyl (IV). The crystal system is monoclinic with space group P21/c. Refined unitcell parameters are a = 13.484(3), b = 11.325(2), c = 17.673(3) Å, and β = 126.613(8)°.

The multicomponent Rietveld profile refinement technique for powder neutron diffraction patterns has been applied to arrive at a quantitative phase analysis of crystalline Ce2Fe17 and α-Fe impurity in a powder specimen of Ce2Fe17.

X-ray powder-diffraction data for Pb2(C2O4)(NO3)2·2H2O were obtained. The crystal system was determined to be monoclinic. The unit-cell parameters were refined to a=10.613(2) Å, b=7.947(2) Å, c=6.189(1) Å, and β=104.48(2)°.

Three new compounds of generalised formula [Cu(LIII)XY]·nH2O [LIII=pymep, terpy; X=I, N3; Y=I, NO3, PF6; n=0,1], pymep (C14H15N3)=N-(6methyl–2-pyridyl–methylene) -2-(2-pyridyl)-ethylamine and terpy (C15H11N3)=2,2′;6′,2″-terpyridine have been prepared by reaction in solution. Crystal data were determined by single-crystal methods. Powder diffraction data and densities determined by a flotation method are also presented.

An X-ray analysis method has been developed for the quantitative analysis of pyrite (FeS2) in coals and lignites. Requiring neither the use of external or internal references, the method linearly relates diffraction peak area in the absorption corrected X-ray diffractogram obtained from the finely powdered coal to the pyrite abundance. The [311] diffraction peak of pyrite (FeS2) has been used to develop the analysis protocol. The Argonne premium coals have been used as the experimental subjects. The abundance of pyrite in each coal has been measured from the absorption corrected diffractograms, which has been constructed from the experimentally measured diffraction intensities and the mass absorption coefficient of each coal sample. The accuracy (accessed from the figure-of-merit and the net count uncertainty associated with the 1.63 Å pyrite peak) as well as the lower limit of detection for pyrite in these coals is presented. The role of the mass absorption coefficient in the conversion of the measured intensity to the absorption corrected intensity is discussed.

Powder data for Ag2SO4were obtained with a conventional diffractometer equipped with a vacuum heating chamber. The transition from the low-temperature orthorhombic phase occurs over a temperature range of about 415° to 425°C and forms a hexagonal phase plus metallic silver. The lack of a sharp transition must be taken into account in high-temperature X-ray diffraction or DSC/DTA studies. The lattice parameters of the high-temperature hexagonal phase are a = 5.531(3), c = 7.456(5)Å at 440°C, λ = 1.540562 Å. Crystal structure determination was not completed because of uncertainty in the chemical composition.

X-ray powder diffraction data are reported for the trihydrated (A3N), the dihydrated (A2N), and the anhydrous ammonium trioxalatoaluminate (III) (AN). A3N is triclinic with space group . A2N and AN are monoclinic with space groups P21/c and P21/n respectively. The stability domains are A3N: –7.8 to 86 °C; A2N: 86 to 102 °C; AN: 102 to 180 °C.

The trihydrated rubidium trioxalato-chromate(III), Rb3(Cr(C2O4)3)·3H2O cristallizes in the monoclinic system with:

The space group is P21/c. CuKα wavelength 1.541778.

The modulation of the lazurite structure has been determined by X-ray diffraction methods. The indexing of satellites on X-ray diffraction powder patterns has been made by means of single crystal X-ray diffraction patterns. The irrationality of the satellite distance from the basic reflections in some specimens of isotropic lazurite confirms the incommensurability of the wavelength of modulation by an edge magnitude of the sodalite subcell and the necessity of a fractional mineral lattice. X-ray diffraction powder data of lazurites with different periods of incommensurate-modulated structure are established. Modulation structure parameters are 0.217 and 0.175, respectively. Indexing of X-ray diffraction powder data of cubic Baikal lazurite suggested by the PDF editorial staff is considered.

By methods of X-ray structure analysis commensurate (one dimensional) and incommensurate (three-dimensional) modulations of the lazurite structure from Baikal deposits are considered. The analysis of the X-ray diffraction powder and single crystal data showed that the one-dimensional (anisotropic) modulation deforms the lazurite cubic structure and is manifested in a broadening and splitting of sublattice lines on the powder diffraction pattern of the mineral. At a three-dimensional modulation, the cubic structure is maintained. It is concluded that a density modulation is a cause of the incommensurate modulation of the lazurite structure. Due to this arrangement, a crystallographic equivalency of subcells is maintained. The cause of the commensurate modulation is an ordered distribution of intraframework units and the displacement modulation where all atoms of the mineral structure participate.

The Semi-manual Structure-sensitive SEARCH-MATCH procedure [Frevel, (1982), Anal. Chem. 54, 691–697] has been automated for the Hewlett-Packard HP 3354 Computer. The software is coded in the interpretive HP LAB BASIC II language. A core file of 1026 selected powder diffraction standards has been compiled covering the common crystalline phases encountered in industry, the ubiquitous crystalline minerals, and prototypes of the more frequently found crystal structures. Solid solutions can be readily identified.

A series of BaO:RxOy:CuO materials has been prepared where R=Y, La, Ce, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. They have been characterized by X-ray powder diffraction methods. All BaR2CuO5 phases, commonly referred to as the “green phases”, are orthorhombic with space group Pbnm(62) and are isostructural. These single phase materials could be prepared with most lanthanides, except for La, Ce, Pr, Nd and Tb. Possible reasons for the exceptions are discussed. Both La and Nd tend to form a brown solid solution of Ba2+2xR4-2xCu2-xO10-2x with a tetragonal space group of P4/mbm(127). The major phases found in the Ce, Pr and Tb compositions are the perovskite-related structures BaRO3, and in the Pr case, Ba2PrCu3O6+x as well. The cell parameters of the green phase materials increase progressively from the Lu compound to the Sm compound: a ranges from 7.0506(6) to 7.2754(4) Å, b from 12. 0534(8) to 12. 4029(7) Å, c from 5.6099(5) to 5. 7602(3) Å, and the cell volume from 476.75(6) to 519.78(4) Å3. A correlation of the crystallographic data with the size of the R elements is given.