1. School of Materials Science and EngineeringGwangju Institute of Science and Technology (GIST) 123 Cheomdangwagi‐ro, Buk‐gu Gwangju 61005 Republic of Korea
2. Electron Microscopy Research CenterKorea Basic Science Institute (KBSI) 169‐148 Gwahak‐ro, Yuseong‐gu Daejeon 34133 Republic of Korea
3. Department of Materials Science and EngineeringKorea Advanced Institute of Science and Technology (KAIST) 291 Daehak‐ro, Yuseong‐gu Daejeon 34141 Republic of Korea