Music, medicine, escape: Austria, Italy, America. As a very young man, Sigmund Weissmann, before he was 18, had seen the prosperous stability and direction of his youth disintegrate, had, through fortunate foresight and mature determination escaped potential disaster, and had found himself, essentially alone, in New York City. That was April 1939. Within 5 years, his early studies completed and military service over, his future had been established with crystallography, and even more particularly, that aspect of it which was related to the “pathology” of metals. He was to establish one of the first laboratories devoted to research of lattice defects and to lay the groundwork for what is now known as Materials Science. Contemporaneous with the operation of this laboratory and as an outgrowth of his own basic connection with the famous “Brooklyn Poly,” Weissmann included, among his manifold teaching, research, and consulting activities, the acceptance of a position as an editor of the Powder Diffraction File, the PDF. The PDF was then just large enough, just important enough and had just that suggestion of an important reach into the future to necessitate an equally important attention from a group of persons schooled and skilled in the most recent techniques of X-ray powder diffraction. Weissmann (metals), Ben Post (organics), of the Brooklyn Polytechnic Institute and J. V. Smith (minerals) (University of Chicago) were the first thus crystographically trained persons to oversee the PDF.

The Metals and Alloys Indexes, published by the International Centre for Diffraction Data, contain four indexes. These are: (a) the alphabetical formula index (AFI); (b) the Pearson symbol code index; (c) the common name index; and (d) the Strukturbericht symbol index. These indexes (which contain metals, alloys, and related phases in the Powder Diffraction File) have been designed to be used independently or in conjunction with the Powder Diffraction File to facilitate the characterization of materials. All data in these indexes have been critically reviewed. The organization, selection of materials, and use of alphabetical formulas are similar to those of standard metallurgical references such as Pearson or Villars and Calvert. The arrangement of the AFI promotes systematic searches for chemical analogs and assists users in locating possible matches when only partial chemical information is available. The structural indexes aid in characterization by correlations to prototype and related structures. Some applications of the indexes are given here.

A two-stage procedure is described for quantitative phase analysis of multicomponent mixtures. Profile analysis of the diffraction pattern of a mixture of phases is done in stage one to obtain integrated intensities with higher accuracy. In stage two a structural refinement is done which yields a scale factor. The weight of a phase in a mixture is proportional to its specific scale factor. The two-stage method was found to be effective for the quantitative phase analysis of a mixture of minerals which always contain structural defects. The procedure was tested first by using two artificial mixtures and then it was applied to natural kaolin. The results obtained were more accurate than some of the other methods used for quantitative analysis; moreover, it can also be used with mixtures containing amorphous or undetermined phases.

YBa2Cu3O7–x films were deposited by chemical vapor deposition (CVD) onto single-crystal MgO, single-crystal Al2O3, and polycrystalline Al2O3 substrates, characterized before and after annealing, and tested for their superconducting properties. The preferred orientation in the films was analyzed (i) with pole figures and (ii) by comparison of experimental x-ray powder diffraction patterns with those calculated for the material using the March–Dollase function to model the degree of preferred orientation. Preferred orientation was significant in as-deposited films, with March coefficients ranging from 0.1–0.5 (random orientation would have a coefficient of 1.0). The (006) pole figures of the films on single crystal substrates exhibited uniquely symmetric patterns. On single-crystal MgO before annealing, a minor secondary orientation of (006) poles in the film was observed in a pattern consistent with the symmetry of major crystallographic directions of MgO. On single-crystal Al2O3 after annealing, a “dual orientation” phenomenon was observed. The high-temperature anneal destroyed the orientation and superconducting properties of the CVD films deposited at high temperatures.

Considering the thermal expansion of silicon at ambient conditions, the lattice parameter will change 0.00032 Å for a 10 °C range. This range is measurable with modern diffraction instrumentation illustrating the importance of knowing the accurate lattice parameter, the temperature of measurement, and the thermal expansion coefficient. The best value for the expansion coefficient is 2.45×10−6/°C.

The new compound, KCr3(SO4)2(OH)6, was prepared by low-hydrothermal synthesis. The structure was refined by the Rietveld technique in space group (Z = 3), a =7.2416(3) Å, c = 17.0788(9) Å, V = 775.63 Å3, Rp = 7.7, Rwp =10.1, RB = 6.8. The compound is isotypic with alunite, KAl3(SO4)2(OH)6. The temperature of decomposition under nitrogen atmosphere to a hitherto unknown form is about 550 K. The water content of alunite-type compounds is discussed.

The accuracy of the unit-cell parameters refined by using the whole-powder-pattern decomposition method is discussed. Powders of W, ZnO, TiO2, BaTiO3 Mg2SiO4, Al2SiO5 (+α-SiO2), and monoclinic ZrO2 were used as test samples. Two internal standard reference materials of Si and CeO2 and two types of powder diffractometers were used for data collections. The systematic peak-shift was corrected by determining the unit-cell parameters and the error function simultaneously during the whole-pattern-fitting. The estimated standard deviations for sample means ranged from <10 ppm (10−6) in cubic symmetry to 20∼50 ppm in monoclinic symmetry. These analyses could be carried out almost automatically in a computation time of less than l min for each sample on a workstation. The use of symmetric experimental profiles, obtained by the suppression of axial divergence, is very effective and of essential importance for improving the accuracy of unit-cell parameters.

Literature data pertaining to the crystal chemistry, crystallography, and X-ray powder-diffraction properties of phases reported in the system BaO-CuOx are compiled. Reported phases include BaCuO2−2.12, BaCuO2.26−2.39, BaCuO2.5, Ba2CuO3+x, Ba2Cu3O5+x, BaCu2O2+x, Ba3Cu5O8, Ba3CuO4, BaCu3O4, Ba3Cu2O4+x, Ba5Cu3O6+x, and BaCu2O3. The existence of some of these phases, however, still has to be verified. Most of these compounds are nonstoichiometric in oxygen. Their oxygen content, and in some cases even their crystal structures, vary with oxygen partial pressure. There are also reported indications that the cations Ba and Cu are not stoichiometric in the cubic BaCuO2-type compounds.