Chen Y.-WFan S.-TCHEE-WEE LIU2021-09-022021-09-02202000223727https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097925359&doi=10.1088%2f1361-6463%2fabc3ec&partnerID=40&md5=0bdf4ffe721b122b6eada33494329d21https://scholars.lib.ntu.edu.tw/handle/123456789/580616In this work, the pathways for polarization switching of hafnium oxide (HfO2) orthorhombic phase were simulated via density functional theory. The energy barriers vary from 30.7 to 69.3 meV/atom depending on the transition states taken in the process of polarization switching. With further analysis, it is found that the pathway via transition state of the Pbcm phase is suitable for the domain-wall motion mechanism for polarization switching but bears the highest energy barrier. On the other hand, the pathways via the tetragonal-like transition state with the lowest energy barrier suggest the uniform switching mechanism. For HfO2 films composed of different sizes of grains, a uniform switching and domain-wall motion mechanism could be activated in small and large grains. ? 2020 IOP Publishing Ltd.Density functional theory; Domain walls; Energy barriers; Optical switches; Polarization; Switching; Different sizes; Domain wall motion; First-principle study; Orthorhombic phase; Polarization switching; Switching mechanism; Transition state; Via density; Hafnium oxidesjournal article10.1088/1361-6463/abc3ec2-s2.0-85097925359