Antiferroelectric behaviors and the role of oxygen migration on fatigue in ZrO₂ films

HfO₂- and ZrO₂-based films exhibiting double hysteresis loops are touted as candidates for next-generation, lead-free energy-efficient devices. Understanding of the origin of double hysteresis in ZrO₂ and of the role of oxygen vacancies in wake-up and fatigue processes, however, have remained elusive. Here, epitaxial single-phase ZrO₂ thin films showing double hysteresis is demonstrated and its mechanism presented. High-resolution scanning transmission electron microscopy, electrical characterization, and density functional theoretical calculations reveal the roles of structural phases and oxygen redistribution in the fatigue process.