Strain-Controlled Formation Energy and Migration of Nitrogen Vacancy in Al<sub>1–<i>x</i></sub>Sc<sub><i>x</i></sub>N: A First-Principles Study
Qinghua Ren, Xin Liu, Zexin Ding, Yuxi Liu, Qunhui Zhou, Qingnan Qian, Guoming Zhang, Haoyuan Li, Nan Wang
Abstract
The impact of strain on the formation energy and migration behavior of nitrogen vacancies (V N s) in Al 1– x Sc x N has been investigated by first-principles calculations. The formation energy of V N s is obtained by total energy calculations. The migration barrier calculation utilizes the climbing nudged elastic band method. It is found that the formation energy of V N s is highly tunable with respect to the strain. The formation energy of V N s increases with the tensile strain increasing to +4% and decreases with the increasing compressive strain to −4%. A minimum formation energy of 4.11 eV is obtained when −4% strain is applied. Furthermore, the migration behavior of V N s is studied by calculating the migration barriers. Calculation results show that the migration barrier is strongly affected by strain. When the strain is −4%, the barrier is 2.46 eV while the barrier is increased to 2.71 eV under +4% strain. Therefore, a tensile strain can prevent the formation and migration of V N s. These findings suggest that strain engineering may serve as a tool for regulating V N s behavior in Al 1– x Sc x N, potentially alleviating the ferroelectric degradations associated with V N s.