Indexed X-ray diffraction powder data for {[Cr3O(C6H5NO2)6(H2O)3](CIO4)7 · 3NaCIO4·0.5(C6H5NO2)· 3H2O}, INICCR (isonicotinato) and {[Cr3O(C6H5NO2)6(H2O)3] (CIO4)7·6NaCIO4·3H2O}, PICOCR (picolinato) are reported. Both INICCR and PICOCR crystallize in the hexagonal space group P63/m. Crystal data determined for INICCR are a = 13.838(3) Å, c = 25.038(8) Å, V = 4152.2 Å3, Dx = 1.71 Mg m−3 (Dm = 1.66(5) Mg m−3), F25 = 26.5(0.020,47) and for PICOCR are a = 13.966(4) Å, c = 24.518(6) Å, V = 4141.5 Å3, Dx = 1.96 Mg m−3 (Dm = 1.94(4) Mg m−3), F21 = 17.9(0.023,51). The JCPDS Diffraction File Number for INICCR is 38-1992 and for PICOCR is 38-1993.

The Debye-Scherrer technique and filtered Cu Kα, radiation were used to obtain powder data for reflections to an angle of 2θ = 155°; a vertical scanning diffractometer was used to obtain intensity data to an angle of 2θ = 99°. The space group is with Z = 4. The lattice parameters of the tetragonal unit cell were measured to be a = 6.189 (1) Å and c = 12.391 (1) Å with c/a = 2.002 The unit cell volume was calculated as U = 474.6 (2) Å3 and the X-ray density as Dx = 6.07 ± 0.003 gm cm−3. By comparing measured and theoretical intensity values, the sublattice distortion parameter x was estimated to be x = 0.227 (12).

X-ray powder data for a maghemite (γ-Fe2O3) used for computer hard disks is reported. This maghemite is cubic with space group P4132.

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.

Fifteen reference patterns of oxides, nitrides, borides, carbides, silicides, and sulfides are included in this report. The general methods of producing these X-ray powder diffraction reference patterns are described in this Journal, Vol. 1, No. 1, pg. 40(1986).

Samples were mixed with one or two internal standards: silicon (SRM640a), silver, tungsten, or fluorophlogopite (SRM675). Expected 2θ values for these internal standards are specified in the methods described (ibid.). Data were measured with a computer controlled diffractometer. The POWDER-PATTERN system of computer programs was used to locate peak positions, to calibrate the patterns, and to perform indexing and least-squares cell refinement. A check on the overall internal consistency of the data was also provided by a computer program.

Intensities were measured as peak heights above background and were read manually from strip charts. To minimize preferred orientation effects, the powders were passed through a 400 mesh sieve and were mixed with an amorphous diluent material, glass powder. Samples were prepared by side-drifting the mixture into the holder or by dusting a thin layer on a glass slide coated with a thin smear of silicone grease.

The support and interest of the ICDD in this project is gratefully acknowledged. The expert guidance of R. Roth of the Ceramics Division on material synthesis and the careful review of the manuscript by S. Block of the Ceramics Division and A. D. Mighell of the Reactor Division are fully appreciated. Acknowledgement is also extended to D. Minor for performing sample analysis by using SEM. In the production of these standard powder patterns, the ability to search NBS CRYSTAL DATA has proven invaluable.

The following fourteen reference patterns of boride, telluride, and oxide ceramics are reported. Included in the fourteen reference patterns are data for six high Tc superconducting oxide and related phases (Ba2CaCu2TI2O8, BaCuEu2O5, BaCuTm2O5, BaCuDy2O5, Ba3.2Cu1.7Y0.8O6.1·xCO2, Sr2Bi2O5). The general methods of producing these X-ray powder diffraction reference patterns are described in this journal, Vol. 1, No. 1, pg. 40 (1986).

Samples were mixed with one or two internal standards: silicon (SRM640a), silver, tungsten, or fluorophlogopite (SRM675). Expected 2θ values for these internal standards are specified in the methods described (ibid.). Data were measured with a computer controlled step-scanning diffractometer. The POWDER-PATTERN system of computer programs was used to locate peak positions, to calibrate the patterns, and 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 method.

Intensities were measured as peak heights above background and were read manually from strip charts. To minimize preferred orientation effects, the powders were passed through a 400 mesh sieve and were mixed with an amorphous diluent, silica gel. Sample mounts were prepared by side-drifting and/or by dusting a thin layer of sample on a glass slide coated with a thin smear of silicone grease.

Seven isotopic molybdates MIIUMo4O16 have been synthesized by solid state reaction with MII = Mg, Mn, Cd, Ca, Hg, Sr, Pb. Single crystals of CaUMo4O16 were obtained. Previously reported as triclinic, this compound is monoclinic, space group P2/n. Unit-cell parameters for the seven compounds are:

MgUMo4O16: a = 11.393(2), b = 6.505(1), c = 7.918(2) Å, β = 89.81(3)°, V = 586.8(5) Å3, Z = 2, Dx = 5.12 Mg m−3;

MnUMo4O16: a = 11.413(2), b = 6.555(1), c = 8.023(1) Å, β = 89.86(2)°, V = 600.2(4)Å3, Z = 2, Dx = 5.18 Mg m−3;

CdUMo4O16: a = 11.427(2), b = 6.607(1), c = 8.144(2) Å3, β = 90.40(2)°, V = 614.8(5)Å3, Z = 2, Dx = 5.37 Mg m−3;

CaUMo4O16: a = 11.443(3), b = 6.653(2), c = 8.239(2)Å, β = 90.51(3)°, V = 627.2(6)Å3, Z = 2, Dm = 4.83(5), Dx = 4.88 Mg m−3;

HgUMo4O16: a = 11.439(3), b = 6.643(1), c = 8.257(2)Å, β = 90.53(3)°, V = 627.4(6)Å3, Z = 2, Dx = 5.73 Mg m−3;

SrUMo4O16: 11.465(3), b = 6.768(2), c = 8.492(2) Å, β = 90.86(3)°, V = 658.8(6)Å3, Z = 2, Dx = 4.88 Mg m−3;

PbUMo4O16: a = 11.470(4), b = 6.813(2), c = 8.557(2)Å, β = 90.88(4)°, V = 668.7(8)Å3, Dx = 5.41 Mg m−3;

Powder diffraction data for each phase are reported.

Neodymium ammonium hydroxynitrate, Nd(OH)2NO3.(NH4NO3)0.5.H2O, has been investigated by means of X-ray powder diffraction. Unit cell dimensions were determined by indexing programs, from diffractometer data obtained with strictly monochromatic CuKα1 radiation. An I orthorhombic cell was found: a = 24.577 (4) Å, b = 7.1488 (16) Å, c = 3.8211 (9) Å. It is shown that the h 1 1 reflections present a selective line broadening.

The following fourteen reference patterns of carbide, nitride, telluride, and oxide ceramics are reported. Included in the fourteen reference patterns are data for three high Tc superconducting oxide related phases (Ba2CuO3, CuSrO2, and Ba2Cu3YO6). The general methods of producing these X-ray powder diffraction reference patterns are described in this journal, Vol. 1, No. 1, pg. 40 (1986).

Samples were mixed with one or two internal standards: silicon (SRM640a), silver, tungsten, or fluorophlogopite (SRM675). Expected 2θ values for these internal standards are specified in the methods described (ibid.). Data were measured with a computer controlled diffractometer. The POWDER-PATTERN system of computer programs was used to locate peak positions, to calibrate the patterns, and 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.