The X-Ray Powder Data File (XRPDF) enables one to identify the compounds in a sample. More often than not, however, a semi-quantitative analysis is wanted. Visual inspection of the pattern may give a vague impression of the composition, but the errors of such a result are usually not within reasonable limits. Clearly a less subjective and more accurate method is wanted. If the necessary data are printed on the cards, such a method will greatly enlarge the usefulness of the File.

This paper presents the first Table of RIR values for quantitative analysis as a model for regular updates which will appear in future issues. Diffractionists interested in the reference intensity method of quantitative analysis are urged to read the criteria for preparing data to continue this Table and then to submit new data.

With the explosive growth in the number of highly automated powder diffraction systems, many types of analyses which were previously considered a specialty analysis are now performed on a routine basis. Algorithms have been developed for measuring peak profiles from which crystallite sizes, residual microstrain, and X-ray crystal structure (Rietveld techniques for example) can be determined. However, these techniques require an instrumental peak profile calibration standard to correct the experimental data for instrumental broadening due to the system optics.

Significant problems are encountered when laboratories try to cross-correlate or reproduce published data due to the lack of a common reference material for instrumental calibration. This is particularly distressing in microstrain and crystallite size calculations which can be dramatically affected by a poor choice of standard materials. Microstrain and crystallite size measurement are becoming increasingly important for the characterization of advanced materials and catalysts.

Trigonal CdSb2O6, prepared as a very crystalline powder by solid state reaction of CdO and Sb2O3, is isostructural with PbSb2O6 Space Group (S.G.) P31m (162), with a = 5.2399(2), c = 4.8045(4) Å, Z = 1 and Dc = 6.57 Mg.m−3. For the refinement of structural parameters from X-ray powder diffraction data two different methods have been employed and compared, both leading to very similar results. The refinements converged to RI = 0.025 using 35 intensities in the incremental optimization technique and to RF = 0.038, RW = 0.033 from 161 reflections in the least-squares refinement.

Synthesis and unit cell parameter refinement of 25 ferroelectric compounds with the tungsten bronze structure are reported. A general chemical formula for these compounds is (A1, A2, C) B10 O30, where specifically A1 and A2 = K, Na, Ba, Sr, Pb, La, Eu, Sm, Y, Bi; C = Li; and B = Nb, Ta, Ti, W. All compounds were prepared by solid state sintering at temperatures ranging from 1100°C to 1380°C. Refined cell parameters (tetragonal with space group P4bm[100]), I/Icor values, calculated densities and Z values are included for the 25 compounds.

Structural and chemical changes in materials can be dynamically observed by using time resolved X-ray Powder Diffraction (XRPD) to collect patterns as these events happen. During calcination of amorphous zirconium hydroxide, Zr(OH)4, and its crystallisation to a metastable tetragonal form of zirconia, ZrO2, patterns have been collected at 10°C temperature intervals during a heating sequence to 500°C. These patterns show both the onset of ordering within the amorphous starting material and the progress of its conversion into crystalline zirconia. Events are recorded within the pattern in the form of peak growth and reduction in amorphous component of the pattern with increasing temperature.

The usefulness of complementing the results of X-ray diffraction (XRD) with an independent technique such as Raman spectroscopy (RS) was demonstrated by the successful identification of the products (TiN and Na-titanates) from the reaction of TiO2 with NaCN. The study of other reactions of NaCN with several Ti-compounds to produce TiN powder led to the development of new syntheses reactions for known [TiP2O7, NaTi2(PO4)3 and NaxTiO2] and for new [(TiO)2P2O7, Na(TiO)PO4 and Na4(TiO)(PO4)2] compounds. The reaction of NaxTiO2 with NaCN produced TiN in the form of whiskers.

Crystal data for four p-dibromobenzene/p-chloroiodobenzene mixed crystals, (pDBB)x(pCIB)1-x, with x = 0.1, 0.4, 0.7, 0.9, synthesized by the fusion-quenching method, and a typical powder diffraction pattern are reported. The unit cell is monoclinic with S.G. = P21/a and Z = 2. Cell parameters of solid solution members varied almost linearly between the end member values.

Indexed X-ray diffraction powder data for three homologous amphiphiles, sodium octyl sulfate (SOS), CH3[CH2]7 OSO3Na, sodium decyl sulfate, CH3[CH2]9OSO3Na (SDS), and sodium dodecyl sulfate CH3[CH2]11OSO3Na (SLS), are reported. Probable space groups for the three compounds are monoclinic P2[3], Pm[6], or P2/m[10]. Refined cell parameters were determined from powder data obtained with a Guinier Camera. Powder data are compared to existing patterns, PDF 4-10 (SOS) and 4-6 (SLS).

Fourteen reference patterns of oxide ceramics are reported. Included in the fourteen reference patterns are data for two high critical temperature superconducting oxide related phases (BaCuHo2O5 and Ba2YCu3O6.56). The general methods of producing these X-ray powder diffraction reference patterns were described previously in this journal (Vol. 1, No. 1, pg. 40 (1986)).

Powder samples for diffraction studies of selected materials have been prepared in this laboratory during the past 15 years using a commercial, slow-speed, diamond saw. The materials powdered include a wide range of ferrous and transition metal alloys as well as geological substances. Before sectioning begins, fresh oil is poured into the oil tray of the saw and the diamond, rim-impregnated, copper blade thoroughly cleaned. A typical blade is 10 cm in diameter and 3 mm thick. Powder produced as the blade cuts through the sample collects in and settles to the bottom of the oil tray. The oil, which bathes the sample surface during cutting and surrounds the powder debris after discharge into the tray, serves to prevent oxidation of most materials.