[SY-B10] Symposium B-10

[SY-B10] Theoretical derivation of the ABVI model from cluster expansion Hamiltonian

^○Antonio Fernandez Caballero^1,2, Jan Wrobel³, Paul Mummery¹, Duc Nguyen-Manh² (1.School of Mechanical, Aerospace and Civil Engineering, University of Manchester, UK, 2.Department of Materials Science and Scientific Computing, CCFE, United Kingdom Atomic Energy Authority, Abingdon OX14 3DB, UK, UK, 3.Faculty of Materials Science and Engineering, Warsaw University of Technology, UI. Wołoska 141, 02-507 Warsaw, Poland, Poland)

In nuclear fusion research, degradation of material microstructure and nanostructure by radiation damage is of interest both from experimentally and modelling perspectives. Modelling from first principles can be used to rationalize mechanisms behind degradation phenomena caused by the simplest type of damage produced by radiation: vacancies and interstitials and their clusters. Recent studies found that density functional theory and kinetic monte carlo can be used to investigate radiation induced segregation and precipitation[1] incorporating both vacancy and interstitial into Ising-like ABVI model Hamiltonian[2]. The kinetic processes of solute transport both by vacancies and interstitials can be captured by a Hamiltonian parametrised by bond energies and derived from DFT.

In this work, we treat multi-body defect-solute or solute-solute interactions as cluster entities from the cluster expanded Hamiltonian of the alloy system containing point defects. Binding energies for elements within defect cluster are expressed in terms of effective interactions parameters found from the cluster expansion of the Hamiltonian of the system containing vacancies and interstitials. Local effects from defect surroundings are incorporated by offseting the binding enery by the cluster expanded reference energy depending on chemical compositions of the surroundings[3,4]. This model can be used to investigate the kinetic simulations of segregation and precipitation of binary alloys under irradiation.





[1] G. Martin, 1980, Phys. Rev. B 21, 2122

[2] C. Huang and J. Marian, 2016, J. Phys.: Condens. Matter 28 425201

[3] J.S. Wrobel, D. Nguyen-Manh, K.J. Kurzydlowski, S.L. Dudarev, 2017, Journal of Physics: Condensed Matter, 29 145403.

[3] A. Fernandez-Caballero, J.S. Wrobel, P.M. Mummery, D. Nguyen-Manh, 2017, J. Phase Equilibrium and Diffusion, 38 391-403.