Neutron scattering studies of short-range order, atomic displacements, and effective pair interactions in a null-matrixNi0.5262Pt0.48crystal

2006 ◽  
Vol 74 (10) ◽  
Author(s):  
J. A. Rodriguez ◽  
S. C. Moss ◽  
J. L. Robertson ◽  
J. R. D. Copley ◽  
D. A. Neumann ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Atomic Displacements ◽  
Effective Pair ◽  
Pair Interactions

Diffuse Neutron Scattering Study of Short-Range Order in Fe0.8Al0.2Alloy

1989 ◽  
Vol 166 ◽  
Author(s):  
Werner Sciiweika
Keyword(s):  
Neutron Scattering ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Chemical Ordering ◽  
Iron Aluminum ◽  
Effective Pair ◽  
Neutron Scattering Study ◽  
Iron Aluminum Alloys ◽  
Diffuse Neutron

ABSTRACTDiffuse neutron scattering experiments have been performed on a single crystal Fe0.8Al0.2at T-1013K. The data are analysed in terms of short-range order and lattice displacements. Effective pair-interactions have been determined by the inverse Monte Carlo method.Further measurements of the temperature dependence of the diffuse scattering reveal a long-range ordered phase with the B32 structure below T∼ 650K. This new phase is related to the influence of the magnetism on the chemical ordering in the, iron-aluminum alloys.

Diffuse Neutron Scattering and Short-Range Order in Alloys – Contrast Variation and Contrast Enhancement by Isotopic Replacement

1986 ◽  
Vol 82 ◽  
Author(s):  
P.P. Mueller ◽  
L. Reinhard ◽  
B. Schoenfeld ◽  
G. Kostorz ◽  
W. Buehrer ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Contrast Variation ◽  
Atomic Displacements ◽  
Cu Alloys ◽  
Zn Alloy ◽  
Ordered State ◽  
Diffuse Neutron

ABSTRACTIn Al-Cu alloys containing Guinier-Preston zones, the scattering contributions due to short-range order and atomic displacements vary differently when the scattering contrast between Al and Cu is changed. The diffuse neutron scattering of Al-Cu single crystals containing 63Cu or 65Cu is compared and evaluated to test the current methods of separating the two scattering contributions. - The nature of a sugggtted ordered state in α-brass is also studied by neutron scattering, using Cu to enhance the scattering contrast in a Cu-30 at.% Zn alloy. A broad diffuse peak is found in powdered, appropriately aged samples, confirming that the first Warren-Cowley short-range order parameter is negative.

A First-Principles Study of Short Range Order in Cu-Zn

1989 ◽  
Vol 166 ◽  
Author(s):  
M. Sluiter ◽  
P.E.A. Turchi ◽  
D.D. Johnson ◽  
F.J. Pinski ◽  
D.M. Nicholson ◽  
...  
Keyword(s):  
First Principles ◽  
Short Range ◽  
Short Range Order ◽  
Alloy System ◽  
Cluster Variation Method ◽  
Range Order ◽  
Variation Method ◽  
Effective Pair ◽  
Cluster Variation ◽  
Pair Interactions

Recently, measurements of short-range order (SRO) diffuse neutron scattering intensity have been performed on quenched Cu-Zn alloys with 22.4 to 31.1 atomic percent (a/o) Zn, and pair interactions were obtained by Inverse Monte Carlo simulation [1]. These results are compared to SRO intensities and effective pair interactions obtained from first-principles electronic structure calculations. The theoretical SRO intensities were calculated with the Cluster Variation Method (CVM) in the tetrahedron-octahedron approximation with first-principles pair interactions as input. More generally, phase stability in the Cu-Zn alloy system is discussed, using ab-initio energetic properties.

Calculation of Pairwise Effective Potentials in the Disordered Ni-22.5at.%Fe Alloy Using Model Potential Method with Account of Size Effect

2021 ◽  
Vol 323 ◽  
pp. 125-129
Author(s):  
Valentin Silonov ◽  
Lkhamsuren Enkhtor
Keyword(s):  
Size Effect ◽  
Short Range ◽  
Short Range Order ◽  
Potential Method ◽  
Model Potential ◽  
Order Parameters ◽  
Range Order ◽  
Disorder Phase Transition ◽  
Effective Potentials ◽  
Atomic Displacements

Pairwise effective potentials in first seventeen shells of the Ni-22.5at.%Fe alloy are calculated using model potential method with account of the linear size effect. Using obtained values of pairwise effective potentials, the short range order parameters on the first seventeen shells of alloy are calculated by Krivoglaz-Clapp-Moss method. The calculated values ​​of the short-range order parameters were fitted to the experimental values ​​by varying the parameters of static atomic displacements. Reliable value of critical temperature of order-disorder phase transition in Ni-22.5at.%Fe alloy was calculated using obtained meanings of pairwise effective potentials.

Structure Investigations on Se1-xTex Melts by Neutron Scattering and X-ray Diffraction

1981 ◽  
Vol 36 (8) ◽  
pp. 880-885 ◽  
Author(s):  
W. Hoyer ◽  
B. Kunsch ◽  
M. Suda ◽  
E. Wieser
Keyword(s):  
Correlation Function ◽  
Neutron Scattering ◽  
Diffraction Data ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nearest Neighbours ◽  
Structure Investigations

Abstract Neutron scattering results on Se1-xTex melts (x = 0.3, 0.6, 0.8) obtained at 460 °C are combined with earlier X-ray diffraction data. The behaviour of the number and distance of nearest neighbours is discussed with respect to chemical short-range order and transition from twofold to three-fold coordination. For Se70Te30 the radial concentration correlation function 4πr2 ρcc(r) has been evaluated. It shows clearly the preferred formation of unlike pairs (Se-Te) within the chains.

Short range order in liquid SeTe system by neutron scattering

1989 ◽  
Vol 156-157 ◽  
pp. 174-176 ◽  
Author(s):  
A. Menelle ◽  
R. Bellissent ◽  
A.M. Flank
Keyword(s):  
Neutron Scattering ◽  
Short Range ◽  
Short Range Order ◽  
Range Order

Short-range ordering of Cu3Au above Tc in the topmost 80 A of a (001) face

1997 ◽  
Vol 12 (1) ◽  
pp. 75-82 ◽  
Author(s):  
M. Kimura ◽  
J. B. Cohen ◽  
S. Chandavarkar ◽  
K. Liang
Keyword(s):  
Short Range ◽  
Short Range Order ◽  
Surface Region ◽  
Antiphase Domain ◽  
Range Order ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Diffuse Intensity ◽  
Near Surface ◽  
Atomic Displacements

The short-range order in the near surface region of the Cu3Au(001) face was investigated above the critical temperature by glancing-incidence x-ray diffraction, measuring the diffuse intensity throughout a two-dimensional region of reciprocal space. This intensity was analyzed quantitatively to obtain the two-dimensional Cowley–Warren short-range-order parameters and atomic displacements. Monte-Carlo simulation based on these values has revealed that the atomic configurations in the surface consist of ordered domains and clusters in a disordered matrix. There is a large number of {10} antiphase domain boundaries (APDB).

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