# Structural Polymorphism Kinetics Promoted by Charged Oxygen Vacancies in HfO$\_2$

Source: [Structural Polymorphism Kinetics Promoted by Charged Oxygen Vacancies in HfO$\_2$](<https://www.sota2.com/research/paper/68fa43b51e209131ce90bf41>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-25T04:27:40.418Z

Authors: Liyang Ma, Shi Liu

Published: 2022-04-20T10:33:28.000Z

## Abstract

Defects such as oxygen vacancy are widely considered to be critical for the performance of HfO2-based devices, and yet atomistic mechanisms underlying various exotic effects such as wake-up and fluid imprint remain elusive. Here, guided by a lattice-mode-matching criterion, we systematically study the phase transitions between different polymorphs of hafnia under the influences of neutral and positively charged oxygen vacancies by mapping out the minimum energy pathways using a first-principles-based variable-cell nudged elastic band technique. We find that the positively charged oxygen vacancy can substantially promote the transition of various nonpolar phases to the polar phase kinetically, enabled by a transient high-energy tetragonal phase and extreme charge-carrier-inert ferroelectricity of the polar $Pca2\_1$ phase. The intricate coupling between structural polymorphism kinetics and the charge state of the oxygen vacancy has important implications for the origin of ferroelectricity in HfO$\_2$-based thin films as well as wake-up, fluid imprint, and inertial switching.

## Recorded benchmark results

A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage.

## Original sources and implementation

[Original paper](<https://arxiv.org/abs/2204.09374>)

[PDF](<https://arxiv.org/pdf/2204.09374.pdf>)