Order-Disorder Transformation in Cu3AAu: A Molecular Dynamics Study

1992 ◽  
Vol 291 ◽  
Author(s):  
Fabrizio Cleri ◽  
Giorgio Mazzone ◽  
Vittorio Rosato Enea
Keyword(s):  
Molecular Dynamics ◽  
Energy Minimization ◽  
Lattice Dynamics ◽  
Short Range ◽  
Cluster Variation Method ◽  
Variation Method ◽  
Cluster Variation ◽  
Method Approach ◽  
Calculated Temperature Dependence ◽  
Iteration Technique

ABSTRACTThe order-disorder transformation in CU3Au has been investigated using a combined Molecular Dynamics and Cluster Variation Method approach. Free energy minimization has been performed using the Natural Iteration technique. The calculated temperature dependence of enthalpy, lattice dynamics, short-range and long-range order parameters have been successfully compared with experimental data.

SHORT RANGE ORDERING AND LOCAL DISPLACEMENT OF ALLOYS STUDIED BY CVM

2012 ◽  
Vol 01 (02) ◽  
pp. 1250018 ◽  
Author(s):  
TETSUO MOHRI
Keyword(s):  
Short Range ◽  
Lattice Distortion ◽  
Cluster Variation Method ◽  
Real Space ◽  
Variation Method ◽  
Diffuse Intensity ◽  
Local Lattice Distortion ◽  
Wide Range ◽  
Local Lattice ◽  
Cluster Variation

Cluster Variation Method (CVM) is a powerful statistical mechanics means to investigate phase equilibria of an alloy. The advantageous feature of the CVM stems from the fact that wide range of atomic correlations which play an important role at the phase transition is efficiently incorporated into the free energy formula. Hence, configurational fluctuation can be systematically studied through the calculations of correlation functions in the real space and short range order diffuse intensity spectrum in the k-space. However, one of the deficiencies of the conventional CVM is the fact that local lattice distortion (local atomic displacement) is not correctly dealt with. In order to improve such shortcomings, Continuous Displacement Cluster Variation Method (CDCVM) has been developed. In the CDCVM, local lattice distortion is mapped onto the configurational freedom of a multi-component alloy on a rigid (uniformly deformable) lattice. With CDCVM, the applicability of CVM is enlarged and the calculations of diffuse intensity spectrum originating from local lattice distortion can be performed.

A data-driven approach to approximate the correlation functions in cluster variation method

2021 ◽  
Author(s):  
Abhishek Kumar Thakur ◽  
Rajendra Prasad Gorrey ◽  
Vikas Jindal ◽  
Krishna Muralidharan
Keyword(s):  
Correlation Functions ◽  
Short Range ◽  
Cluster Variation Method ◽  
Data Driven ◽  
Variation Method ◽  
Internal Variables ◽  
Data Driven Approach ◽  
Cluster Variation ◽  
Bcc Phase

Abstract The cluster variation method (CVM) is one of the thermodynamic models used to calculate phase diagrams considering short range order (SRO). This method predicts the SRO values through internal variables referred to as correlation functions (CFs), accurately up to the cluster chosen in modeling the system. Determination of these CFs at each thermodynamic state of the system requires solving a set of nonlinear equations using numerical methods. In this communication, a neural network model is proposed to predict the values of the CFs. This network is trained for the BCC phase under tetrahedron approximation for both ordering and phase separating systems. The results show that the network can predict the values of the CFs accurately and thereby Helmholtz energy and the phase diagram with significantly less computational burden than that of conventional methods used.

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.

scholarly journals A Cluster Variation Method Approach to the Problem of Low-Temperature Statistics of a Class of Ising Models

2001 ◽  
Vol 42 (11) ◽  
pp. 2157-2164 ◽  
Author(s):  
V. M. Mati´c ◽  
L. T. Wille ◽  
N. Dj. Lazarov ◽  
M. Mili´c
Keyword(s):  
Low Temperature ◽  
Cluster Variation Method ◽  
Ising Models ◽  
Variation Method ◽  
Cluster Variation ◽  
Method Approach
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