A Generalized Ising Model for studying Alloy Evolution under Irradiation and its use in Kinetic Monte Carlo Simulations

TL;DR

This paper introduces a generalized Ising Hamiltonian model, ABVI, for simulating alloy evolution under irradiation, incorporating defect transport and validated through kinetic Monte Carlo simulations.

Contribution

The paper develops a new ABVI Hamiltonian that includes interstitial and vacancy defects, extending existing models for more accurate irradiation damage simulations.

Findings

The ABVI model accurately reproduces irradiation damage microstructures.

Kinetic Monte Carlo simulations with ABVI match published results.

The model links Hamiltonian parameters to first-principles bond energies.

Abstract

We derive an Ising Hamiltonian for kinetic simulations involving interstitial and vacancy defects in binary alloys. Our model, which we term `ABVI', incorporates solute transport by both interstitial defects and vacancies into a mathematically-consistent framework , and thus represents a generalization to the widely-used ABV model for alloy evolution simulations. The Hamiltonian captures the three possible interstitial configurations in a binary alloy: A-A, A-B, and B-B, which makes it particularly useful for irradiation damage simulations. All the constants of the Hamiltonian are expressed in terms of bond energies that can be computed using first-principles calculations. We implement our ABVI model in kinetic Monte Carlo simulations and perform a verification exercise by comparing our results to published irradiation damage simulations in simple binary systems with Frenkel pair defect production and several microstructural scenarios, with matching agreement found.