A method for the correction of peak position for the Seemann-Bohlin X-ray diffractometer, useful for practical application, is presented. The position of diffraction peaks is largely influenced by both the displacement of specimen from the diffractometer circle and the shift of the X-ray tube focus. The described correction method has been used for investigation of thin layers, especially for the precise determination of both lattice parameter and stresses in thin films. The application of the method is illustrated on samples of TiN and ZrN coatings deposited on steel substrates and additionally covered with a thin film of Si or Ta or TaC powder used as an internal standard.

The crystal structure of monoclinic CuF2 has been refined by the Rietveld method from X-ray powder diffraction data. The structure is monoclinic, space group P21/n, a = 3.2973(2), b = 4.5624(3), c = 4.6157(3) Å, β = 83.293(3)°, V = 68.96(2) Å3, with Cu+2 at (0,0,0) and F−1 at (−0.04176(68), 0.29410(35), 0.29410(35)). Final RB = 0.97%, RP = 1.99%, Rwp = 2.32%, RWP(expected) = 1.46%. The structure has a rutile-type arrangement, but with a monoclinic distortion that produces a highly distorted octahedral coordination around the Cu2+ ion with equatorial and apical Cu-F distances of 1.92 and 2.32 Å respectively.

A previously manually operated film comparator used to evaluate Guinier films has been automated as a film scanner of the flat film type. The film movement is controlled by a stepper motor and the intensity of the transmitted light is recorded as a function of position on the film. A personal computer controls the stepper motor and records the measurements of the transmitted light intensity. The data quality is judged from refinements of lattice constants for α-SiO2 and ZrO2. The powder pattern for Pb2Sr2Ho0.625Ca0.375Cu3O8 and a high temperature study of the thermal expansion of GeO2 are presented.

Cd3(BO3)2 was prepared by a solid state reaction between B(OH)3 and Cd(OH)2 at low temperatures ranging between 523° and 623° and at a pressure of 10−4 – 10−5 Hg mm. The crystal structure has been refined by Rietveld analysis of X-ray powder diffraction data. The compound crystallizes in the orthorhombic system, space group Pnnm, Z = 2, with cell parameters of a = 5.967(5) Å, b = 4.78 (0) Å and c = 9.009(5) Å.

Indexed X-ray powder diffraction data are reported for two energetic materials, oxalylhydroxamic acid and 2-diazo-4, 6-dinitrophenol (DDNP). For these two compounds, powder diffraction data calculated from single-crystal structure determinations are also presented and compared to the experimentally observed powder diffraction data. To evaluate the reliability of the experimentally obtained intensities, an intensity figure of merit, IX(N), based on an average percent difference between observed and calculated intensities for a limited number of strong and moderately-strong lines is proposed as a more useful measure of agreement than R1. For N lines with Icalc > X% relative intensity, IX(N) is defined as

This is compared to

which involves a summation over all lines.

A technique is described for the preparation of Guinier camera samples which are permanent and can be stored indefinitely in microslide file cases.

A critical review of all the reported structures and powder diffraction patterns in the uranium telluride system has been undertaken. Our recommendations are:

1. Structures that are correct:

• Cubic – UTe: no experimental pattern exists. Retain calculated 15–865.

• Cubic – U3Te4: retain poor quality 12-610 but adopt the pattern calculated here.

• Cubic U2Te3: no experimental pattern exists. Adopt pattern calculated here.

• Orthorhombic UTe2: Adopt the new pattern of Boehme et al.

• Monoclinic αUTe3: Adopt the new pattern of Boehme et al.

• Orthorhombic βUTe3: Adopt the pattern calculated here.

• Orthorhombic UTe5: Adopt the new pattern of Boeheme et al.

2. Structures in need of refinement:

• Orthorhombic U2Te3: Adopt pattern calculated here over 34-807.

• Hexagonal U7Te12: Adopt pattern calculated here but retain 24-1368.

• Orthorhombic UTe1.78: Adopt pattern calculated here and retain our modified 21-1404 reported for U4Te7.

• Orthorhombic UTe2.5: Adopt pattern calculated here.

• Orthorhombic UTe3.4: Accept recent pattern of Boehme et al.

3. Phases for which no structures or reliable patterns exist:

• Orthorhombic U3Te4: no published pattern.

• Tetragonal U3Te5: three patterns 21-1407, 34-766 and 34-896 exist but all are of very poor quality.

4. Phases which probably do not exist:

• Tetragonal UTe1.77

• Tetragonal UTe2

• Cubic UTe2

• U3Te7 (21-1402)

• U3Te8 (21-1406)

The binary phase diagram of para-dibromobenzene and para-chloroiodobenzene is characterized by a partial miscibility with a peritectic invariant. Unit cell parameters have been determined and their variation analyzed as a function of composition.

An extension of the Nelson-Riley absorption correction of Debye-Scherrer diagrams is given. This enables the calculation of the shifts of the reflection angles if the absorption coefficient is known. Alternatively, these shifts can be found by including the corresponding coefficient in a least-squares lattice constant refinement.

An iterative external standard method of X-ray diffraction is presented to overcome the difficulties of preferred orientation and peak overlap encountered in quantitative phase analysis. Instead of using only a single line intensity in the traditional external standard technique, all the reflection data are used in the calculation. The accuracy and applicability of this method was tested on a series of two-phase powder mixtures with known composition. The results show markedly good agreement with the actual values. As an example, the analysis was applied to the data collected from an as plated electrodeposited Zn-Fe coating. The determined phase composition of the coating was found to be 88.2 +/− 5.3 wt % δ-phase and 11.8 +/− 0.7 wt % η -phase.

With the help of Boulle's metathesis reaction, we have succeeded in preparing the compound [NH3(CH2)2NH3]2·P207. We describe its chemical preparation and main crystallographic features. The bis(ethylenediammonium) diphosphate salt is monoclinic, space group C2/c, with Z = 4. Unit cell parameters and powder diffraction data for this salt are reported.

X-ray powder diffraction patterns of orthorhombic- and rhombohedral-distorted perovskite PrNiO3 obtained at room temperature, 200°, 400°, 500°, and 600°C were analyzed and evaluated. An examination of the diffraction profiles shows essentially no line broadening indicating that the PrNiO3 powders synthesized by solid state reaction are well-crystallized and probably strain-free. The reliability and accuracy of the patterns were evaluated, and the figures-of-merit were in triple digits for the 500° and 600°C patterns of the rhombohedral phase and double digits for the more complex orthorhombic diffraction patterns recorded at room-temperature, 200°, and 400°C. Values of lattice parameters refined from the observed diffraction peak positions agree with those obtained from the Rietveld whole-pattern fitting analysis to within 1–2 × 10−4.

Three members of the family [Cu(C14H15N3)X2]·nH2O [X = N3(n = 1); NCS and Br(n = 0)], C14H15N3, = N-(2′-(6-methyl) pyridyl) methylene-2-(2′-pyridyl)ethylamine)] (pymep), have been prepared by reaction in solution. Crystal data determined with the aid of single crystal methods, powder diffraction data, and densities determined by flotation methods are presented.

This report is one of a series on the nomenclature for spectrochemical analysis issued by the International Union of Pure and Applied Chemistry. It concerns a new notation for X-ray emission lines and absorption edges, to be called IUPAC NOTATION, which replaces the existing Siegbahn notation. It is based upon the energy level designation and has the advantage of being simple and easy to apply to any kind of transition. Moreover, it is consistent with the notations used in electron spectroscopy.

The document first discusses the terms currently used in X-ray spectroscopy and then describes the principles of the IUPAC notation with reference to the X-ray levels and the X-ray transitions. The correspondence between Siegbahn and IUPAC notations for all X-ray lines is given in a table. Finally, the document gives the units and conversion factors used in the X-ray range.

A powder diffraction pattern and unit cell data for nitroguanidine, C(NH2)2NNO2 are presented. The orthorhombic space group Fdd2 (43) has been confirmed by single crystal methods.

A series of five synthetic tetrahedrite-group minerals has been prepared and examined using powder X-ray diffraction in order to update current powder data and provide a validation test of cell dimension prediction equations. The tetrahedrites (nominally (Cu10X2)Sb4S13 with X = Zn, Cd, Mn, Hg and Fe) have the following properties: zincian tetrahedrite, a = 10.3833 (1) Å, Dx = 4.974 (1) g/cm3, F30 = 264 (0.004, 31), M20 = 279; cadmian tetrahedrite, a = 10.5066 (1) Å, Dx = 5.073 (1) g/cm3, F30 = 208 (0.004, 37), M20 = 249; manganoan tetrahedrite, a = 10.4384 (1) Å, Dx = 4.822 (1) g/cm3, F30 = 274 (0.003, 33), M20 = 302; mercurian tetrahedrite, a = 10.5071 (1) Å, Dx = 5.570 (1) g/cm3, F30 = 150 (0.006, 35), M20 = 156; ferroan tetrahedrite, a = 10.3630 (1) Å, Dx = 5.002 (1) g/cm3, F30 = 253 (0.004, 33), M20 = 281. The experimental unit cell dimensions obtained in this study are in excellent agreement with calculated values produced using regression equations developed previously.

X-ray powder diffraction data for the compound 2,2′,2″-triaminotriethylamine-trihydrochloride, N-(CH2−CH2−NH2)3 (HCL)3 are reported. The crystals are cubic and the space group is P213 with a = 10.8734(12) Å. Dx = 1.320Mg/m3. The data were obtained both by photographic and diffractometric methods.

X-Ray powder diffraction data for the compound 2,2′,2″-triamino-triethylamine-Ni(II)-di-thiocyanate were obtained by transmission diffractometric methods at 20°C - 22°C. Two data sets were collected with CuKα1 radiation (λ = 1.54056 Å) one with Si as an internal standard (a = 5.430825 Å) and one without.

The deep blue crystals are orthorhombic of space group P212121. Peak positions were corrected by aid of the Si peaks in the first data set. Refinements of lattice constants from indexed reflections yielded the following values: a = 10.8524(18) Å; b = 14.7249(16) Å; c = 8.6511(11) Å; Dx = 1.542 Mg/m3. The second data set was used for a Rietveld refinement. The lattice constants obtained by this method are: a = 10.8451(5) Å; b = 14.7148 Å; c = 8.6447(4) Å.