About this Abstract |
Meeting |
MS&T21: Materials Science & Technology
|
Symposium
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Probing Defect Properties and Behavior under Mechanical Deformation and Extreme Conditions
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Presentation Title |
A Statistical Approach for Atomistic Calculations of Vacancy Formation Energy and Chemical Potentials in Concentrated Solid-solution Alloys |
Author(s) |
Yongfeng Zhang, Anus Manzoor, Chao Jiang , Dilpuneet Aidhy |
On-Site Speaker (Planned) |
Yongfeng Zhang |
Abstract Scope |
This talk presents a statistical approach for atomistic calculations of the vacancy formation energy in concentrated solid-solution alloys. Demonstrated using a random FeCrNi ternary alloy, a general formulation is given for applications in random, concentrated alloys with any numbers of components. The approach calculates the mean vacancy formation energy based on the total energies of a defect-free reference supercell and defected supercells each with a vacancy, without separate calculations for chemical potentials, avoiding the additional computation cost and the associated uncertainty. The chemical potential of each component can be back derived in a self-consistent manner to give the distribution of vacancy formation energy. It is also found that, with the same mean vacancy formation energy, a broader distribution may lead to a lower equilibrium vacancy concentration at a given temperature, indicating the critical importance of statistically obtaining the full distribution of vacancy formation energy. |