Poly Crystallography Inc.

Naperville, IL, United States

Poly Crystallography Inc.

Naperville, IL, United States
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Knight D.A.,Savannah River National Laboratory | Zidan R.,Savannah River National Laboratory | Lascola R.,Savannah River National Laboratory | Mohtadi R.,Toyota Motor Corporation | And 6 more authors.
Journal of Physical Chemistry C | Year: 2013

The recent discovery of a new class of negative ions called hyperhalogens allows us to characterize this complex as belonging to a unique class of materials called hypersalts. Hyperhalogen materials are important while serving as the building blocks for the development of new materials having enhanced magnetic or oxidative properties. One prime example of a hydperhalogen is the Al(BH4)4 - anion. Aluminum borohydride (17 wt % H) in itself is a volatile, pyrophoric compound that has a tendency to release diborane at room temperature, making its handling difficult and very undesirable for use in practical applications. Here we report that the combination of Al(BH4)3 with the alkaline metal borohydride KBH 4 results in the formation of a new compound KAl(BH4) 4 which is a white solid that exhibits remarkable thermal stability up to 154 C and has the typical makeup of a hypersalt material. Using a variety of characterization tools and theoretical calculations, we study and analyze the physical characteristics of this compound and show its potential for stabilizing high hydrogen capacity, energetic materials. © 2013 American Chemical Society.


Yan Y.G.,Wuhan University of Technology | Yan Y.G.,U.S. National Institute of Standards and Technology | Wong-Ng W.,U.S. National Institute of Standards and Technology | Kaduk J.A.,Poly Crystallography Inc. | And 3 more authors.
Applied Physics Letters | Year: 2011

We have demonstrated the effect of gradients in phase composition and microstructure of p-type CeFe4Sb12 melt-spun ribbons on Seebeck coefficient by using a thermoelectric (TE) screening tool in conjunction with x-ray diffraction. The spatial Seebeck coefficient variation was found to correlate with the changes in the phase composition and microstructure. The observed gradient was the result of a postannealing effect caused by the thermal lag between the contact surface with the roller and the free surface. Our results illustrate the application of our screening tool to the three-dimensional variation in Seebeck coefficient in a model TE material. © 2011 American Institute of Physics.


Liu G.,U.S. National Institute of Standards and Technology | Wong-Ng W.,U.S. National Institute of Standards and Technology | Yang Z.,U.S. National Institute of Standards and Technology | Kaduk J.A.,Poly Crystallography Inc. | And 2 more authors.
Journal of Solid State Chemistry | Year: 2010

The complex phase relationships near the BaO-poor region of the quaternary BaSmYCuO oxide system prepared in pure air (pO2=22 kPa, 950 °C) and in 0.1% O2 (pO2=100 Pa, 810 °C) have been determined. This investigation also included the subsolidus compatibilities in ten subsystems (Ba-Sm-Y-O, Ba-Sm-Cu-O, Ba-Y-Cu-O, Sm-Y-Cu-O, Ba-Sm-O, Ba-Y-O, Ba-Cu-O, Sm-Y-O, Sm-Cu-O, and Y-Cu-O), and the homogeneity range of five solid solutions (Ba(Sm xY2-x)CuO5, (Sm,Y)2O3, (Sm,Y)2CuO4, (Y,Sm)2Cu2O 5, and Ba(Sm,Y)2O4). The single phase range of the superconductor solid solution, (Ba2-xSmx)(Sm 1-yYy)Cu3O6z, and the phase compatibilities in its vicinity, which are particularly important for processing, are described in detail. The phase equilibrium data of the BaSmYCuO system will enable the improvement of the intrinsic superconducting properties of second-generation wires, and facilitate the flux-pinning process.


Wong-Ng W.,U.S. National Institute of Standards and Technology | Kaduk J.A.,Poly Crystallography Inc. | Espinal L.,U.S. National Institute of Standards and Technology | Suchomel M.R.,Argonne National Laboratory | And 2 more authors.
Powder Diffraction | Year: 2011

The family of zeolitic imidazolate framework (ZIF) compounds is efficient sorbent materials that can be used for catalytic, ion exchange, gas storage, and gas separation applications. A high-resolution reference X-ray powder diffraction pattern for one of the ZIF members, bis(2-methylimidazolyl)-zinc, C8H10N4Zn (commonly known as ZIF-8), was determined using synchrotron diffraction data obtained at the Advanced Photon Source (APS) in Argonne, IL. The sample was confirmed to be cubic I-43m, with a = 17.01162(6) Å, V = 4932.08 Å3, and Z = 12. The reference X-ray powder diffraction pattern has been submitted for inclusion in the Powder Diffraction File (PDF). © 2011 International Centre for Diffraction Data.


Wong-Ng W.,U.S. National Institute of Standards and Technology | Huang Q.,U.S. National Institute of Standards and Technology | Levin I.,U.S. National Institute of Standards and Technology | Woicik J.C.,U.S. National Institute of Standards and Technology | And 3 more authors.
Powder Diffraction | Year: 2012

The crystal structure of type I clathrate Ba8Ni4Ge42 has been determined using neutron powder diffraction, transmission electron microscopy (TEM, for possible superlattice), and extended X-ray absorption fine structure (EXAFS) measurements. Ba8Ni4Ge42 is cubic with the space group Pm n and unit-cell parameter a = 10.6769(2) Š(D x = 5.988 g cm-3). The structure combines two different types of polyhedra: the dodecahedron (Ge20, 20-atom cage with 12 pentagonal faces) and the tetrakaidecahedron (Ge24, 24-atom cage with 12 pentagonal and 2 hexagonal faces). Each unit cell contains two Ge20 dodecahedra and six Ge24 tetrakaidecahedra. The Ge20 dodecahedra are linked via the interstitial 6c positions. The framework structure is formed by a tetrahedrally bounded network of Ge atoms, whereas Ba atoms reside inside the Ge20 and Ge24 cavities at the 2a and 6d crystallographic positions, respectively. Ni atoms exclusively occupy the 6c positions located on the hexagonal faces of the larger tetrakaidecahedra; no Ni atoms are found in the smaller dodecahedra that consist of pentagonal faces. A local structure study using EXAFS supports the coexistence of Ge and Ni on the 6c site. Electron diffraction in TEM reveals no detectable Ge/Ni ordering. © 2012 International Centre for Diffraction Data.


Brazdil J.F.,Ineos Technologies Inc. | Toft M.A.,Ineos Technologies Inc. | Lin S.S.-Y.,Ineos Technologies Inc. | McKenna S.T.,Ineos Technologies Inc. | And 4 more authors.
Applied Catalysis A: General | Year: 2015

Acrylonitrile is a major chemical intermediate used in the production of a wide range of chemical and polymer products. Central to the commercial process is a proprietary catalyst consisting of a complex mixture of metal oxides containing a bismuth-containing molybdate phase that is active and selective for propylene ammoxidation to acrylonitrile. Among the most active and selective is a solid solution of bismuth and cerium molybdate. Solid state structural studies were undertaken to characterize this active phase. The results show that the mixed bismuth-cerium molybdate consists of a solid solution phase having the scheelite-related structure of cerium molybdate with a monoclinic unit cell. Analysis of the cation site occupancy using synchrotron X-ray diffraction indicates that bismuth preferentially occupies the Ce(3) site of the monoclinic cerium molybdate structure. It is therefore possible to singularly identify the structure of the active site for propylene ammoxidation given that bismuth is a necessary constituent of a site for selective propylene (amm)oxidation. The proposed active site consists of bismuth located next to a cation vacancy in the structure, presumably in order to accommodate its lone pair of electrons. Bismuth serves as the site for the rate determining α-hydrogen abstraction from propylene to form an allyl intermediate and subsequent nitrogen insertion and loss of lattice oxygen. The bismuth site is surrounded by two cerium cations in this active site configuration. Thus the model that emerges from this study is Bi3+ and Ce3+ in a molybdate structural framework with cerium readily able to undergo Ce3+ 虠 Ce4+ redox that facilitates lattice oxygen transfer to the active site as required by the operative Mars-van Krevelen mechanism for selective propylene ammoxidation. The presence of two cerium cations adjacent to bismuth as a key component of the active site is expected to promote the rapid re-oxidation of the catalytic site effecting enhanced catalytic performance with respect to selective product yields and productivity. © 2015 Elsevier B.V. All rights reserved.


Liu G.,U.S. National Institute of Standards and Technology | Wong-Ng W.,U.S. National Institute of Standards and Technology | Kaduk J.A.,Poly Crystallography Inc. | Cook L.P.,U.S. National Institute of Standards and Technology
Physica C: Superconductivity and its Applications | Year: 2010

Chemical interactions between the Ba2YCu3O6+x superconductor and the LaMnO3 buffer layers employed in coated conductors have been investigated experimentally by determining the phases formed in the Ba2YCu3O6+x-LaMnO 3 system. The Ba2YCu3O6+x-LaMnO 3 join within the BaO-(Y2O3-La2O3)- MnO2-CuOx multi-component system is non-binary. At 810 °C (pO2 = 100 Pa) and at 950 °C in purified air, four phases are consistently present along the join, namely, Ba2-x(La1+x- yYy)Cu3O6+z, Ba(Y2-xLax)CuO5, (La1-xYx)MnO3, (La,Y)Mn2O5. The crystal chemistry and crystallography of Ba(Y2-xLax)CuO5 and (La1-xYx)Mn2O5 were studied using the X-ray Rietveld refinement technique. The Y-rich and La-rich solid solution limits for Ba(Y2-xLax)CuO5 are Ba(Y1.8La0.2)CuO5 and Ba(Y0.1La1.9)CuO5, respectively. The structure of Ba(Y1.8La0.2)CuO5 is Pnma (No. 62), a = 12.2161(5) Å, b = 5.6690(2) Å, c = 7.1468(3) Å, V = 494.94(4) Å3, and Dx = 6.29 g cm-3. YMn2O5 and LaMn2O5 do not form solid solution at 810 °C (pO2 = 100 Pa) or at 950 °C (in air). The structure of YMn2O5 was confirmed to be Pbam (No. 55), a = 7.27832(14) Å, b = 8.46707(14) Å, c = 5.66495(10) Å, and V = 349.108(14) Å3. A reference X-ray pattern was prepared for YMn2O5.


Wong-Ng W.,U.S. National Institute of Standards and Technology | Kaduk J.A.,Poly Crystallography Inc. | Liu G.,U.S. National Institute of Standards and Technology
Powder Diffraction | Year: 2011

Two selected members of the homologous series An+2BBn′O3n+3 (A=Sr and Ca; B and B′=Co) have been investigated for their crystal structures because of their potential applications as thermoelectric materials. A combined Rietveld refinement and spin-polarized magnetic geometry optimization technique was employed for the structural studies. Both the n=3 member, (Sr0.8Ca0.2)5Co4O12, and the n=4 member, Sr6Co5O15, have distorted hexagonal perovskite-related structures that possess one-dimensional cobalt oxide chains separated by alkaline-earth cations. The linear chains consist of one unit of CoO6 trigonal prism alternating with n units of CoO6 octahedra. Crystal structures and reference powder X-ray diffraction patterns of (Sr0.8Ca0.2)5Co4O11 [P3c1, a=9.4196(2) Å, c=19.9857(6) Å, V=825.83 Å3, and Dx=5.358 g/cm3] and Sr6Co5O15 [R32, a=9.497 64(12) Å, c=12.3956(2) Å, V=968.34 Å3, and Dx=5.455 g/cm3] are reported. © 2011 International Centre for Diffraction Data.


Wong-Ng W.,U.S. National Institute of Standards and Technology | Yang Z.,U.S. National Institute of Standards and Technology | Kaduk J.A.,Poly Crystallography Inc. | Cook L.P.,U.S. National Institute of Standards and Technology | And 2 more authors.
Physica C: Superconductivity and its Applications | Year: 2011

This paper describes the crystal chemistry and crystallography of the products of reaction of Ba2YCu3O6+x with the SrTiO3 buffer, which is a model system for coated conductors. A systematic study of the chemical interactions of Ba 2YCu3O6+x and SrTiO3 was conducted under 100 Pa pO2 (0.1% pO2). The compounds determined based on the reactions of the bulk Ba2YCu 3O6+x and SrTiO3 include (Ba,Sr)YTi2O8.5, (Ba,Sr)2YCu3O 6+x, (Ba,Sr)TiO3, (Ba,Sr)2TiO 4, and CuO. The crystal structures of (Ba,Sr)RTi2O 8.5 (R = Y and lanthanides), (Ba,Sr)TiO3, (Ba,Sr) 2TiO4, which have been previously reported, are reviewed. Detailed description of the (Ba, Sr)2RCu3O 6+x (R = Pr, Nd, Sm, Eu, Gd, Dy, Ho, and Er) structure, as determined using X-ray Rietveld refinements, is given. Reference patterns of selected reaction products have been prepared and submitted to the Powder Diffraction File (PDF). © 2011 Elsevier B.V. All rights reserved.

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