Yoon, Seungjae Han, Gyuseung Ye, Kun Hee Jeong, Taeyoung Hwang, Cheol Seong Choi, Jung-Hae 2024-01-19T09:01:59Z 2024-01-19T09:01:59Z 2023-08-31 2023-08 0021-8979 https://pubs.kist.re.kr/handle/201004/113408 The effects of in-plane strain on the dielectric constant of the Be0.25Mg0.75O rock salt superlattice are investigated through ab initio thermodynamics calculations. Based on a previous report that the long apical Be-O bond increased the dielectric constant, the in-plane compressive strain dielectric constant is expected to increase the dielectric constant. Unlike the zero-strain case, the apical Mg-O bonds also contribute to the increase in the dielectric constant under compressive strain. However, small Be ions tend to occupy narrow spaces in the MgO-based rock salt structure, which can lead to an increase in dielectric constant even under in-plane tensile strain, depending on the local position of Be ions and its interaction with O ions. At higher temperatures, several configurations under strain showed a significant increase in the dielectric constant due to the elongation of the apical Be-O bond. Considering temperature and strain comprehensively, this study suggests that the Be0.25MgO0.75O superlattice under -2% in-plane compressive strain could be a promising candidate structure for achieving a high-? value of approximately 30. English American Institute of Physics A first principles study of the in-plane strain effects on the dielectric constant of high-κ Be0.25Mg0.75O superlattice Article 10.1063/5.0159353 1 Journal of Applied Physics, v.134, no.5 Journal of Applied Physics 134 5 Y scie scopus 001043990000002 2-s2.0-85168098121 Physics, Applied Physics Article TOTAL-ENERGY CALCULATIONS PHASE-TRANSITION BEO MEMORY