Exafs Studies of Defects in β-Alumina Superionic Conductors

1984 ◽  
Vol 41 ◽  
Author(s):  
W. L. Roth ◽  
R. Wong
Keyword(s):  
Solid Solution ◽  
Neutron Diffraction ◽  
Bond Strength ◽  
Exafs Spectroscopy ◽  
Superionic Conductors ◽  
Rhombohedral Structure ◽  
Substantial Fraction ◽  
X Ray ◽  
Local Structures ◽  
Preliminary Study

AbstractThe local structures of Zn and Co in solid solution in Na βN–alumina have been investigated using EXAFS spectroscopy. These additives are members of a group that must be incorporated in βN–alumina to stabilize the rhombohedral structure. It is found that they are tetrahedrally coordinated to four oxygen atoms. The N–O bond distances are larger than the Al–O distance in β–alumina and larger than the Al(2)–O distances in disordered crystals determined by x-ray and neutron diffraction. The bonds about individual ions and mixtures of ions are consistent with predictions from bond-strength-bonddistance theory. A preliminary study of Na β–alumina that has been implanted with in and annealed indicates that a substantial fraction of the Mn is tetrahedrally coordinated.

Study of GeSi solid solution crystals by X-ray topography and neutron diffraction

1983 ◽  
Vol 213 (2-3) ◽  
pp. 483-487 ◽  
Author(s):  
M.L. Kozhukh ◽  
I.N. Belokurova ◽  
S.B. Vakhrushev ◽  
A.N. Titkov ◽  
I.L. Shul'pina
Keyword(s):  
Solid Solution ◽  
Neutron Diffraction ◽  
X Ray

Structural Studies of Hydrogen Storage Alloys using X-ray/Neutron Diffraction and Total Scattering

2011 ◽  
Vol 1334 ◽  
Author(s):  
Yumiko Nakamura ◽  
Hyunjeong Kim ◽  
Saishun Yamazaki ◽  
Kouji Sakaki ◽  
Thomas Proffen ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Pair Distribution Function ◽  
Ex Situ ◽  
Structural Studies ◽  
Hydrogen Storage Alloys ◽  
Total Scattering ◽  
X Ray ◽  
Local Structures ◽  
Rich Domain

ABSTRACTCrystal and local structures and hydrogen occupation of Mg containing materials, (Mg,Ca)Nix (x = 2, 3) intermetallic compounds and a MgCo metastable alloy, have been investigated using in-situ and ex-situ X-ray/neutron diffraction and total scattering.A C15 Laves phase (Mg0.67Ca0.33)Ni2 showed isotropic lattice expansion upon hydrogenation. Mg and Ca occupied the same site randomly. It has two hydrogen sites, Mg(Ca)2Ni2 site and M(Ca)Ni3 site.Mg2CaNi9, MgCa2Ni9, and CaNi3 compounds consisted of MgZn2-type (Mg,Ca)2Ni4 cell and CaCu5-type CaNi5 cell stacking along the c-axis. The MgZn2-type cell was occupied by only Mg in Mg2CaNi9, and randomly occupied by both Mg and Ca in MgCa2Ni9. Expansion of this cell strongly depended on the composition: larger expansion was observed in a Ca-rich composition.Local structure of a Mg-Co alloy synthesized by mechanical alloying has been studied using the PDF (Pair Distribution Function) method. The analysis suggested that material contained two 1-2 nm domains with different compositions and local structures, i.e. Mg-rich and Co-rich domains, and hydrogen was located only in the Mg-rich domain.

Structures of (ND4)2V(SO4)2.6D2O and (ND4)2V0.45Zn0.55(SO4)2.6D2O At 5.8 K by Neutron Diffraction

1988 ◽  
Vol 41 (9) ◽  
pp. 1289 ◽  
Author(s):  
RJ Deeth ◽  
BN Figgis ◽  
JB Forsyth ◽  
ES Kucharski ◽  
PA Reynolds
Keyword(s):  
Solid Solution ◽  
Neutron Diffraction ◽  
Bond Length ◽  
Crystal Structures ◽  
The Other ◽  
Tetragonal Distortion ◽  
X Ray Diffraction ◽  
Tutton Salts ◽  
X Ray

The crystal structures of (ND4)2V(SO4)2.6D2O and (ND4)2V0.45Zn0.55(SO4)2.6D2O have been determined at 5.8 K by neutron diffraction. The 663 and 857 unique reflections measured respectively refined to give R(F2) 0.035 and 0.045. The crystals are monoclinic, P21/a, isostructural with the other members of the series of Tutton salts. The V-O bond length of 211.8 pm [210.4 pm for mean (V/Zn)-O in the solid solution with Zn] is intermediate between these for the Mn (214.9 pm) and the Ni(205.5 pm) salts. It is shorter than the value determined by X-ray diffraction at 295 K. The major departure from a regular VO6 octahedron is a shortened V-O(9) bond, such as is observed in the other Tutton salts, to give a tetragonal distortion.

On the limitations of the Borie–Sparks method to determine short-range-order coefficients from diffraction experiments

1986 ◽  
Vol 19 (3) ◽  
pp. 164-167 ◽  
Author(s):  
E. Bubeck ◽  
V. Gerold
Keyword(s):  
Experimental Data ◽  
Solid Solution ◽  
Neutron Diffraction ◽  
Size Effects ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Atomic Size ◽  
X Ray ◽  
Crucial Problem

In order to determine short-range order in a solid solution from diffuse X-ray or neutron diffraction experiments the separation of atomic size effects from the experimental data is a crucial problem. It is demonstrated by a model calculation that a clear improvement of the separation method proposed by Borie & Sparks is obtained if the range of measurement is extended to include the first Brillouin zone.

scholarly journals Experimental and computational study of the magnetic properties of ZrMn2−xCoxGe4O12

2017 ◽  
Vol 46 (21) ◽  
pp. 6921-6933 ◽  
Author(s):  
Diming Xu ◽  
Matthew Sale ◽  
Maxim Avdeev ◽  
Chris D. Ling ◽  
Peter D. Battle
Keyword(s):  
Solid Solution ◽  
Magnetic Properties ◽  
Neutron Diffraction ◽  
Computational Study ◽  
X Ray Diffraction ◽  
Ceramic Method ◽  
X Ray

Polycrystalline samples in the solid solution ZrMn2−xCoxGe4O12 (x = 0.0, 0.5, 1.0, 1.5 and 2.0) have been prepared using the ceramic method and characterised by a combination of magnetometry, X-ray diffraction and neutron diffraction.

ChemInform Abstract: Single Crystal X-Ray and Powder Neutron Diffraction Study of the A-La2O3 Type Bi1-xPbxF2xyO1.5-0.5x-xy Solid Solution

ChemInform ◽  
1989 ◽  
Vol 20 (50) ◽  
Author(s):  
J.-C. CHAMPARNAUD-MESJARD ◽  
D. MERCURIO ◽  
B. FRIT ◽  
C. FOLLET-HOUTTEMANE ◽  
J.-C. BOIVIN ◽  
...  
Keyword(s):  
Solid Solution ◽  
Neutron Diffraction ◽  
Single Crystal ◽  
Diffraction Study ◽  
Neutron Diffraction Study ◽  
X Ray ◽  
Powder Neutron Diffraction

A method, based upon `bond-strength' calculations, for finding probable lithium sites in crystal structures

1978 ◽  
Vol 34 (6) ◽  
pp. 901-905 ◽  
Author(s):  
K. Waltersson
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Bond Strength ◽  
Powder Diffraction ◽  
Three Dimensional ◽  
The Other ◽  
Data Sets ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Bond Strengths

A method for finding probable Li positions in a given oxygen matrix in crystals is described. It is formally based upon bond strength-bond length discussions. The sums of bond strengths for simulated Li atoms are calculated and printed in three-dimensional maps. The method is tested on nine structures containing Li atoms. In five of these the Li sites are known from neutron diffraction studies, in two from X-ray powder diffraction data sets, and in the other two from X-ray single-crystal investigations. The calculated Li coordinates in all the tests are in fair agreement with the experimentally observed positions. The method is therefore likely to provide an auxiliary tool for determining Li sites in X-ray crystal structure studies.

Local structure in the disordered solid solution ofcis- andtrans-perinones

2016 ◽  
Vol 72 (3) ◽  
pp. 416-433 ◽  
Author(s):  
Jaroslav L. Teteruk ◽  
Jürgen Glinnemann ◽  
Winfried Heyse ◽  
Kristoffer E. Johansson ◽  
Jacco van de Streek ◽  
...  
Keyword(s):  
Solid Solution ◽  
Crystal Structures ◽  
Disordered Systems ◽  
Lattice Energy ◽  
Orientational Disorder ◽  
Polycyclic Aromatic Compound ◽  
X Ray ◽  
Local Structures ◽  
Polycyclic Aromatic ◽  
Anisotropic Displacement Parameters

Thecis- andtrans-isomers of the polycyclic aromatic compound perinone, C26H12N4O2, form a solid solution (Vat Red 14). This solid solution is isotypic to the crystal structures ofcis-perinone (Pigment Red 194) andtrans-perinone (Pigment Orange 34) and exhibits a combined positional and orientational disorder: In the crystal, each molecular position is occupied by either acis- ortrans-perinone molecule, both of which have two possible molecular orientations. The structure ofcis-perinone exhibits a twofold orientational disorder, whereas the structure oftrans-perinone is ordered. The crystal structure of the solid solution was determined by single-crystal X-ray analysis. Extensive lattice-energy minimizations with force-field and DFT-D methods were carried out on combinatorially complete sets of ordered models. For the disordered systems, local structures were calculated, including preferred local arrangements, ordering lengths, and probabilities for the arrangement of neighbouring molecules. The superposition of the atomic positions of all energetically favourable calculated models corresponds well with the experimentally determined crystal structures, explaining not only the atomic positions, but also the site occupancies and anisotropic displacement parameters.

The Precipitation of Si in AlCuSi Thin Films

1973 ◽  
Vol 31 ◽  
pp. 34-35 ◽  
Author(s):  
R. M. Anderson
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Heat Treatment ◽  
Solid Solution ◽  
Integrated Circuit ◽  
Copper Film ◽  
Solution Concentration ◽  
X Ray ◽  
Silicon Thin Films ◽  
Before And After

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.

Defect structures of Nb1+αS2 sulfidation scales

1992 ◽  
Vol 50 (1) ◽  
pp. 38-39
Author(s):  
Chuxin Zhou ◽  
L. W. Hobbs
Keyword(s):  
Stacking Faults ◽  
Rhombohedral Structure ◽  
Stacking Sequence ◽  
Defect Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plane Normal ◽  
Lower Case ◽  
Sulfur Layer ◽  
Two Phases

One of the major purposes in the present work is to study the high temperature sulfidation properties of Nb in severe sulfidizing environments. Kinetically, the sulfidation rate of Nb is satisfactorily slow, but the microstructures and non-stoichiometry of Nb1+αS2 challenge conventional oxidation/sulfidation theory and defect models of non-stoichiometric compounds. This challenge reflects our limited knowledge of the dependence of kinetics and atomic migration processes in solid state materials on their defect structures.Figure 1 shows a high resolution image of a platelet from the middle portion of the Nb1+αS2 scale. A thin lamellar heterogeneity (about 5nm) is observed. From X-ray diffraction results, we have shown that Nb1+αS2 scale is principally rhombohedral structure, but 2H-NbS2 can result locally due to stacking faults, because the only difference between these 2H and 3R phases is variation in the stacking sequence along the c axis. Following an ABC notation, we use capital letters A, B and C to represent the sulfur layer, and lower case letters a, b and c to refer to Nb layers. For example, the stacking sequence of 2H phase is AbACbCA, which is a ∼12Å period along the c axis; the stacking sequence of 3R phase is AbABcBCaCA to form an ∼18Å period along the c axis. Intergrowth of these two phases can take place at stacking faults or by a shear in the basal plane normal to the c axis.

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