XRF and XRD measurements made on a single pressed powder briquet can be combined to give more quantitative information than either technique employed alone. Speed of analysis and simplification of sample preparation are also enhanced. The algorithm presented here uses multiple linear regression of the concentrations of one or more elements on the corrected X-ray diffraction intensities of the phases containing them. The data reduction program runs on a microcomputer. Data are presented to show its application to mineralogical analysis of artificial mixtures of quartz, microcline (a feldspar) and calcite.

Crystalline structures of one single- and two multi-layer magnetic CoCrTa films were characterized by X-ray powder diffraction technique. Structural parameters such as crystalline phase, preferred orientation, crystallite size and microstrain (which control the magnetic properties) have been determined. Polycrystalline diffractions from lattice planes parallel and perpendicular to the surface of a film were obtained with the specimen in reflection and in transmission, respectively. Phase identification of the ternary alloy (Co85Cr15)90Ta10 magnetic layers of the specimens indicated a disordered solid solution of Cr and Ta in Co, and the alloy has a hexagonal close-packed (h.c.p.) (A3) structure. Line broadening analysis showed crystallite size anisotropy and columnar CoCrTa grains. The crystal growth was disrupted by the nonmagnetic “amorphous” spacing layers in the multi-layer specimens. The disruption increased with the decreasing magnetic layer thickness. Compared to those of the single-layer film, a lesser (00l) basal plane preferred orientation with a larger perpendicular c-axis dispersion, smaller crystallite sizes and higher microstrains at L≥50Å were obtained in the multi-layer specimen consisting of eight 500Å thick magnetic layers. The magnetic particles were found to be poorly crystallized in the multi-layer specimen where the thicknesses of the 33 magnetic layers were limited to 150Å each.

New crystal data for the intermetallic sigma phase in the Mo-Ru-system are reported and the indexing of the pattern given in the Powder Diffraction File has been extended. The material is tetragonal, P42/mnm (No. 136) with a = 9.5652(4) Å; c = 4.9362(3) Å; Vol = 451.63(7) Å3, Dc = 10.79 Mg m−3 for the composition Mo.63Ru.37, and a = 9.5569(21) Å; c = 4.9418(20) Å; Vol = 451.35(38) Å3, Dc = 10.75 Mg m−3 for Mo.70Ru.30.

Powder data were obtained by the Guinier method and the indexing was corroborated by single crystal data. Transition to the superconducting state took place in the interval 6.8 K – 8.8 K.

The “hook effect” observed in the Warren-Averbach analysis of X-ray diffraction peaks from multiple layer thin films of copper has been investigated theoretically and experimentally. The strengths of the “hook effect” for films of different layer thicknesses were analyzed. The results showed definite correlation between the strengths of the “hook effect” and the grain size distributions in 1, 4, and 19-layer copper films.

Accurate, digitized, spectral distribution data are given for CuKα radiation, comprising the profiles of CuKα1, CuKα2 and CuKα3,4. Three consistent analytical procedures are detailed for locating the peak of an X-ray emission line and are found to be superior to the conventional graphical centerline method.

X-ray powder diffraction was used as an analytical technique for the solid state synthesis of selective oxidation catalysts with large surface area. Qualitative analysis was used to determine the minimum temperature at which the synthesis was complete. Quantitative diffraction was used to analyze mixtures of isomorphous antimonates. Results indicated that the final mixtures are independent of the method of preparation, i.e., mixing or impregnation.

X-ray powder diffraction analysis of the complex of Benzo-15-Crown-5 (B-15-Crown-5) with NaClO4 displays a monoclinic crystal system with refined unit cell parameters of a = 8.829(3)Å, b = 8.327(3)Å, c = 24.21(2)Å, ß = 99.18(1)Å, V = 1757.1(1)Å3, Z = 4, and Dx = 1.48 g/cm3. The space group, P21/c, and the unit cell dimensions, determined by a single crystal diffraction analysis, agree well with those of the powder analysis. X-ray powder diffraction analysis of the complex of B-15-Crown-5 with KI displays a tetragonal crystal system with refined unit cell dimensions of a = b = 17.869(3)Å, c = 9.761(3)Å, V = 3116.7(1)Å3, Z = 4, and Dx = 1.50 g/cm3. The space group, P4/n, and the unit cell dimensions, determined by a single crystal diffraction analysis, agree well with those of die powder diffraction analysis. The powder and single crystal analyses of the two complexes indicate that in the solid phase, B-15-Crown-5 forms a 1:1 complex with Na+ and a 2:1 complex with K+. The variation in the complexation mode of B-15-Crown-5 with different cations, partially explains the lack of selectivity of this crown ether towards Na+, while from considerations of the cavity size alone this crown ether was expected to be considerably selective towards this cation.

Based on high purity constituents ternary AlFeSi intermetallic phases were prepared and annealed at 600°C for a month with compositions close to that of αH-AlFeSi (Al8Fe2Si) phase (∼8 wt.% Si, ∼32 wt.% Fe). The powder diffraction patterns and the chemical compositions of the different αH-AlFeSi intermetallic compounds formed as major components in the samples were investigated by X-ray powder diffraction and electron microprobe analysis, respectively.

A complete powder diffraction pattern is presented for the αH-AlFeSi intermetallic phase with 8 wt.% silicon and 33.5 wt.% iron content formed almost congruently. The refined cell parameters are given as

a = 12.4056 (7) Å

c = 26.236 (2) Å

Comparing the observed intensities with intensities calculated from single crystal data, gave very good agreement.

The lattice parameters of αH-AlFeSi phases with different silicon content were refined by the least-squares method. A contraction of the unit cell caused by the increase of the silicon content in the phase can be observed. Relative changes of the cell dimensions for 1 wt. % increase in silicon are −0.06%, −0.09 % and −0.21 % for the parameters a and c and for the unit cell volume, V, respectively.

External standard and internal standard calibrations are important procedures for achieving high accuracy in X-ray powder diffraction studies. The theoretical basis as well as procedures for obtaining calibration curves are given. Methods and examples of selecting Standard Reference Materials (SRMs) which are produced and issued by the National Bureau of Standards (NBS), and procedures of sample preparation with these standards are also described. Three examples are presented to indicate the value of using SRMs.

The trihydrated potassium trioxalato-chromate(III), K3(Cr(C2O4)3).3H2O, crystallizes in the monoclinic system with:

the space group is P21/c.

X-ray powder diffraction and single-crystal data are reported for a series of isomorphous compounds with the general chemical composition (Fe,Al)3(K,NH4,H3O)H14 (PO4)8·4H2O. The compounds are monoclinic with space group C2/c. Unit-cell parameters were determined on the mixed salt (Fe0.84,Al0.16)3KH14(PO4)8·4H2O, as obtained from sludge precipitated in commercial shipping-grade wet-process phosphoric acid. Single-crystal studies and refined powder diffraction data provided unit-cell parameters of a= 16.908(9) Å, b = 9.588(2) Å, c = 17.539(5) Å, and β = 91.06(4)°.

Two molybdates MIV (MoO4)2 (with MIV = Hf or Zr) were synthesized by solid state reaction between MIVO2 and MoO3. Zirconium molybdate undergoes a reversible phase transition at 952 K.

Hf(MoO4)2 and H.T. Zr(MoQ4)2, obtained as single crystals, are trigonal, space group with Z = 6; the cell dimensions are respectively a = 10.1005(3), c = 11.7230(5)Å; V = 1035.76(11)Å3; Dm(298 K) = 4.78(4), Dx = 4.792 Mg m−3 and a = 10.1409(3), c = 11.7097(5)Å; V = 1042.88(11)Å3; Dm (298 K) = 3.91(4), Dx = 3.926 Mg m−3.

L.T. Zr(MoO4)2, indexed by the Visser automatic indexing program (1969) was found to be monoclinic, possible space group P2, P21 or Pm with Z = 4; the cell dimensions are a = 9.7557(5), b = 7.9373(5), c = 7.4631(4)Å, β = 97.959°(5); V = 572.3(5)Å Dm(298 K) = 4.74(5), Dx = 4.770 Mg m−3. Powder diffraction data were obtained at 293 K on a counter diffractometer with Ni-filtered copper radiation ( = 1.5418 Å).

The trihydrated ammonium trioxalato-chromate(III) (NH4)3 (Cr(C2O4)3)·3H2O crystallizes in the triclinic system with:

.

Possibilities and restrictions of least-square methods for mica cell refinement are briefly described. If diffractometric raw data are precise and accurate, and if geometrical errors are properly corrected, a cell refinement (determination of ao, bo, cO, β) can be carried out rapidly, but the reliability of obtained data has to be evaluated carefully.

The following sixteen reference patterns of boride, silicide, nitride and oxide ceramics represent the second group of reference patterns measured at the National Bureau of Standards under the project “High Quality Reference Patterns and Total Digital Powder Patterns of Technologically Important Ceramic Phases”. Included in the sixteen reference patterns are data for two high Tc superconducting oxide phases (CuSr0.2La1.8O4 and Ba2Cu3YO7) plus one related phase (BaCuY2O5). In addition to these new phases, five other patterns represent phases previously not contained in the PDF and eight represent major corrections to data in the file. The general methods of producing these X-ray powder diffraction reference patterns are described in this journal, Vol. 1, No. 1, pg. 40 (1986).

Indexed powder diffraction data for Lu(OH)3 are reported. The compound is cubic, Im3(No. 204), with a = 8.2221(3)Å, V = 555.84Å3, Z = 8, Dm = 5.36(4)Mg m−3 (Dx = 5.40Mg m−3). The refined cell parameter was determined by employing a Siemens Debye-Scherrer camera (Cu radiation, Ni filter). The indexed data were evaluated according to the quantitative figures of merit FN and M20 (F29 = 20(0.028,51) and M20 = 43.5). A thermal gravimetric analysis is presented. The JCPD S Diffraction File No. for Lu(OH)3 is 38–1500.

Potassium calcium phosphate, KCa PO4.H2O, has been investigated by means of X-ray powder diffraction. Unit cell dimensions were determined from diffractometer data obtained with strictly monochromatized Cu Kα1 radiation, by indexing programs. A C-centered monoclinic cell was found: a =7.5834(9) Å, b = 8.1568(11) Å, c = 7.6541(8) Å, β= 102.975 (9)°.

The following fifteen reference patterns of boride, silicide and oxide ceramics represent the first group of ceramic phases measured at the National Bureau of Standards under the project “High Quality Reference Patterns and Total Digital Powder Patterns of Technologically Important Ceramic Phases”. The support and interest of the JCPDS-ICDD in this project is gratefully acknowledged.

The general methods of producing these X-ray powder diffraction reference patterns are described in this journal, Vol. 1, No. 1, pg. 40(1986).

The following new or updated patterns are submitted by the JCPDS Research Associateship at the National Bureau of Standards. The patterns are a continuation of the series of standard X-ray diffraction powder patterns published previously in the NBS Circular 539, the NBS Monograph 25, and in this journal. The methods of producing these reference patterns are described in this journal, Vol. 1, No. 1, p. 40 (1986).

The data for each phase apply to the specific sample described. A sample was mixed with one or two internal standards: silicon (SRM640a), silver, tungsten, or fluorophlogopite (SRM675). Expected 2-theta values for these standards are specified in the methods described (ibid.). Data, from which the reported 2-theta values were determined, were measured with a computer controlled diffractometer. Computer programs were used to locate peak positions and calibrate the patterns as well as to perform variable indexing and least squares cell refinement. A check on the overall internal consistency of the data was also provided by a computer program.