Structure of covalently bonded glass-forming melts: A full partial-structure-factor analysis of liquidGeSe2

1991 ◽  
Vol 67 (1) ◽  
pp. 97-100 ◽  
Author(s):  
Ian T. Penfold ◽  
Philip S. Salmon
Keyword(s):  
Factor Analysis ◽  
Structure Factor ◽  
Partial Structure ◽  
Glass Forming ◽  
Partial Structure Factor ◽  
Covalently Bonded

On the determination of partial structure functions in small-angle scattering exemplified by Al89Ni6La5alloy

2009 ◽  
Vol 42 (2) ◽  
pp. 323-325 ◽  
Author(s):  
Armin Hoell ◽  
Dragomir Tatchev ◽  
Sylvio Haas ◽  
Jörg Haug ◽  
Peter Boesecke
Keyword(s):  
Neutron Scattering ◽  
Absorption Edge ◽  
Small Angle ◽  
Structure Factor ◽  
Alloy Sample ◽  
Partial Structure ◽  
X Ray ◽  
Partial Structure Factor ◽  
X Ray Scattering ◽  
Ray Scattering

A comparison between the resonant scattering curve obtained by anomalous small-angle X-ray scattering at the X-ray absorption edge of Ni and the complementary small-angle neutron scattering curve from an Al89Ni6La5alloy sample is reported. The sample does not comply with the two-phase approximation. The two resulting scattering curves are approximately proportional to each other in this particular case. The anomalous small-angle X-ray scattering resonant curve at the Ni absorption edge equals the Ni–Ni partial structure factor and, owing to the favourable neutron scattering lengths of Ni, La and Al, the neutron scattering curve is also proportional to that partial structure factor.

Partial Structure Factor of Amorphous Cu0.57Zr0.43 Alloy Determined by TOF Pulsed Neutron Diffraction

1978 ◽  
Vol 45 (5) ◽  
pp. 1773-1774 ◽  
Author(s):  
Toshio Kudo ◽  
Tadashi Mizoguchi ◽  
Noboru Watanabe ◽  
Nobuo Niimura ◽  
Masakatsu Misawa ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Structure Factor ◽  
Partial Structure ◽  
Partial Structure Factor ◽  
Pulsed Neutron

Phasing of resonant anomalous X-ray reflectivity spectra and direct Fourier synthesis of element-specific partial structures at buried interfaces

2007 ◽  
Vol 40 (2) ◽  
pp. 290-301 ◽  
Author(s):  
Changyong Park ◽  
Paul A. Fenter
Keyword(s):  
Structure Factor ◽  
Imaging Method ◽  
Partial Structure ◽  
Fourier Synthesis ◽  
X Ray ◽  
Partial Structure Factor ◽  
Buried Interfaces ◽  
Partial Structures ◽  
Model Independent

A formalism for model-independent determination of element-specific partial structures at buried interfaces using the phase-dependent behavior of resonant anomalous X-ray reflectivity (RAXR) data is described. Each RAXR spectrum (i.e.reflectivityversusenergy at a fixed momentum transfer near the absorption edge of interest) is uniquely constrained by the amplitude and phase of the resonant partial structure factor with pre-determined non-resonant total structure factor and anomalous dispersion corrections of the resonant species. The element-specific partial density distribution is then imaged by discrete Fourier synthesis with the partial structure factor. The utility of this approach is demonstrated in the comparison of Rb+and Sr2+distributions at muscovite (001)–aqueous solution interfaces derived by model-independent and model-dependent approaches. This imaging method is useful for rapid determination of complex buried interfacial structures where element-specific atomic distributions are poorly constrained by conventional X-ray reflectivity analysis.

The structure of some models for aqueous nickel chloride solutions in the high concentration range

1980 ◽  
Vol 33 (9) ◽  
pp. 1889 ◽  
Author(s):  
HL Friedman ◽  
JB Dudowicz
Keyword(s):  
Structure Factor ◽  
Particle Number ◽  
Nickel Chloride ◽  
Structural Features ◽  
Particle Number Density ◽  
Partial Structure ◽  
High Concentration ◽  
Partial Structure Factor ◽  
The Monte Carlo Method ◽  
High Concentration Range

The Monte Carlo method has been applied to a charged soft-sphere model for the ions in aqueous NiCl2 to calculate the Ni-Ni partial structure factor. For some of the models investigated, the wave vector location k0 of the first peak in the partial structure factor is given closely by the equation ko = 2πp+1/3, where p+ is the particle number density of the Ni2+ ions. This is the behaviour that has been found experimentally by Enderby and coworkers and that has been interpreted in terms of a 'quasilattice' structure in the solutions. The present results indicate that rather general and non-specific structural features are sufficient to account for the experimental data.

The structure of molten and glassy 2:1 binary systems: an approach using the Bhatia—Thornton formalism

1992 ◽  
Vol 437 (1901) ◽  
pp. 591-606 ◽  
Keyword(s):  
Structure Factor ◽  
Binary Systems ◽  
Range Order ◽  
Partial Structure ◽  
Systematic Analysis ◽  
Glass Forming ◽  
Structure Factors ◽  
Total Structure Factor ◽  
Diffraction Patterns ◽  
Total Structure

A systematic analysis of those liquid binary 2:1 systems (denoted MX 2 ), for which experimental partial structure factors are available from the isotopic substitution method in neutron diffraction, is made using the Bhatia-Thornton (BT) formalism.Particular attention is paid to the origin of the first sharp diffraction peak (FSDP ), which occurs in the measured diffraction patterns for some of the MX 2 systems, since it appears, from recent studies, that this feature is a signature of directional bonding. It is found that FSDPS can occur in all three BT partial structure factors S xB (k). A FSDP feature in the concentration-concentration partial structure factor S cc (k) is not, however, pronounced except in the case of MgCl 2 and the glass forming network melts ZnCl 2 and GeSe 2 . To the extent that these systems can be regarded as ionic melts a FSDP in S cc (k) implies a non-uniformity in the charge distribution on the scale of the intermediate-range order (IRO). The structure of molten GeSe 2 is compared with the structures of molten ZnCl 2 , glassy GeS 2 and glassy Si0 2 . Although the GeSe 2 and ZnCl 2 melts have different short-range order, there are similarities in the observed IRO which can be attributed to the arrangement of the electropositive species M. The essential features of the measured total structure factor for glassy GeS 2 can be reproduced by using the molten GeSe 2 S zB (k). This result lends support to the notion that the S zB (k) for liquid GeSe 2 (and ZnCl 2 ) are characteristic of both the liquid and glassy states of other network glass forming systems. The structures of molten GeSe 2 (or ZnCl 2 ) and glassy Si0 2 are, however, found to be different. The observed discrepancies are largest in the region of the FSDP which signifies pronounced differences in the nature of the IRO for these systems.

Neutron Diffraction with the Metallic Glass Ni31Dy69 ( + 10 a/o D) Using Isotopic Substitution

1985 ◽  
Vol 40 (2) ◽  
pp. 191-192
Author(s):  
A. Wildermuth ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Amorphous Alloy ◽  
Neutron Diffraction ◽  
Metallic Glass ◽  
Structure Factor ◽  
Isotopic Substitution ◽  
Diffraction Experiment ◽  
Partial Structure ◽  
Neutron Diffraction Experiment ◽  
Partial Structure Factor ◽  
Structure Factors

By neutron diffraction using the method of isotopic substitution with the amorphous alloy Ni31Dy69 the partial structure factors SNiNi, SDyDy and SNiDy were obtained, furthermore with the same specimen containing 10 a/o deuterium a partial structure factor SDD resulted. For the evaluation of SDD it was necessary to perform the neutron diffraction experiment with an alloy whose both components were zero scattering isotopic mixtures of Ni or Dy, respectively.

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