Optimal migration path of Ag in HfO2: A first-principles study*
Dai Yue-Hua†a), Chen Zhena), Jin Boa), Li Ninga), Li Xiao-Fengb)
       
Barrier sites of Ag atoms along the five paths. Smaller balls represent O atoms, bigger balls denote the Hf atoms, and middling balls refer to the Ag atoms. For each of paths A , B , and C , site 3 on the left, site 2, and site 3 on the right are the initial site, transition site and the final site of Ag atom, respectively. For each of paths D and E , site 3 on the left, site 2, and site 1 on the right are the initial site, transition site and final site of Ag atom, respectively.