Oxygen vacancy-induced strengthening and toughening in (K,Na)NbO3-based piezoceramics revealed via nanoindentation

Abstract Dislocations are emerging as a pivotal factor for tailoring ceramics’ functional and mechanical properties. The introduction of point defects, notably oxygen vacancies, is unavoidable during the conventional sintering process in polycrystalline ceramics. Understanding the interplay between...

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Main Authors: Zhidong Zhang, Bin Yang, Longyu Chen, Zaoli Zhang, Jinming Guo
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:Nature Communications
Online Access:https://doi.org/10.1038/s41467-025-62424-3
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author Zhidong Zhang
Bin Yang
Longyu Chen
Zaoli Zhang
Jinming Guo
author_facet Zhidong Zhang
Bin Yang
Longyu Chen
Zaoli Zhang
Jinming Guo
author_sort Zhidong Zhang
collection DOAJ
description Abstract Dislocations are emerging as a pivotal factor for tailoring ceramics’ functional and mechanical properties. The introduction of point defects, notably oxygen vacancies, is unavoidable during the conventional sintering process in polycrystalline ceramics. Understanding the interplay between dislocations and oxygen vacancies is necessary for its profound implications. This work implements an innovative approach to regulate the dislocation-based incipient plasticity and creep behavior in (K0.5Na0.5)NbO3-based ceramics through oxygen vacancy engineering via CuO “hard” doping. Nanoindentation pop-in tests reveal that increasing oxygen vacancy concentrations significantly promotes the nucleation and activation of dislocations. Theoretical calculations based on density functional theory further corroborate that oxygen vacancies contribute to a decrease in Peierls stress and total misfit energy, facilitating dislocation nucleation and activation. Nanoindentation hardness and creep behavior demonstrate that oxygen vacancy impedes dislocation mobility due to solute strengthening and pinning effects. The effect of oxygen vacancies is elucidated through diverse mechanisms related to the interaction between dislocations and oxygen vacancies at different stages. This oxygen vacancy-induced strengthening and toughening strategy displays a significant potential to improve the mechanical properties of piezoelectric ceramics, while still maintaining high electrical performance.
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institution Kabale University
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publisher Nature Portfolio
record_format Article
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spelling doaj-art-d2dd7cb172f742259272e75ceb6591582025-08-20T03:43:09ZengNature PortfolioNature Communications2041-17232025-07-0116111210.1038/s41467-025-62424-3Oxygen vacancy-induced strengthening and toughening in (K,Na)NbO3-based piezoceramics revealed via nanoindentationZhidong Zhang0Bin Yang1Longyu Chen2Zaoli Zhang3Jinming Guo4Hubei Key Laboratory of Polymer Materials, Ministry-of-Education Key Laboratory of Green Preparation and Application for Functional Materials, School of Materials Science and Engineering, Hubei UniversityHubei Key Laboratory of Polymer Materials, Ministry-of-Education Key Laboratory of Green Preparation and Application for Functional Materials, School of Materials Science and Engineering, Hubei UniversityHubei Key Laboratory of Polymer Materials, Ministry-of-Education Key Laboratory of Green Preparation and Application for Functional Materials, School of Materials Science and Engineering, Hubei UniversityErich Schmid Institute of Materials Science, Austrian Academy of SciencesHubei Key Laboratory of Polymer Materials, Ministry-of-Education Key Laboratory of Green Preparation and Application for Functional Materials, School of Materials Science and Engineering, Hubei UniversityAbstract Dislocations are emerging as a pivotal factor for tailoring ceramics’ functional and mechanical properties. The introduction of point defects, notably oxygen vacancies, is unavoidable during the conventional sintering process in polycrystalline ceramics. Understanding the interplay between dislocations and oxygen vacancies is necessary for its profound implications. This work implements an innovative approach to regulate the dislocation-based incipient plasticity and creep behavior in (K0.5Na0.5)NbO3-based ceramics through oxygen vacancy engineering via CuO “hard” doping. Nanoindentation pop-in tests reveal that increasing oxygen vacancy concentrations significantly promotes the nucleation and activation of dislocations. Theoretical calculations based on density functional theory further corroborate that oxygen vacancies contribute to a decrease in Peierls stress and total misfit energy, facilitating dislocation nucleation and activation. Nanoindentation hardness and creep behavior demonstrate that oxygen vacancy impedes dislocation mobility due to solute strengthening and pinning effects. The effect of oxygen vacancies is elucidated through diverse mechanisms related to the interaction between dislocations and oxygen vacancies at different stages. This oxygen vacancy-induced strengthening and toughening strategy displays a significant potential to improve the mechanical properties of piezoelectric ceramics, while still maintaining high electrical performance.https://doi.org/10.1038/s41467-025-62424-3
spellingShingle Zhidong Zhang
Bin Yang
Longyu Chen
Zaoli Zhang
Jinming Guo
Oxygen vacancy-induced strengthening and toughening in (K,Na)NbO3-based piezoceramics revealed via nanoindentation
Nature Communications
title Oxygen vacancy-induced strengthening and toughening in (K,Na)NbO3-based piezoceramics revealed via nanoindentation
title_full Oxygen vacancy-induced strengthening and toughening in (K,Na)NbO3-based piezoceramics revealed via nanoindentation
title_fullStr Oxygen vacancy-induced strengthening and toughening in (K,Na)NbO3-based piezoceramics revealed via nanoindentation
title_full_unstemmed Oxygen vacancy-induced strengthening and toughening in (K,Na)NbO3-based piezoceramics revealed via nanoindentation
title_short Oxygen vacancy-induced strengthening and toughening in (K,Na)NbO3-based piezoceramics revealed via nanoindentation
title_sort oxygen vacancy induced strengthening and toughening in k na nbo3 based piezoceramics revealed via nanoindentation
url https://doi.org/10.1038/s41467-025-62424-3
work_keys_str_mv AT zhidongzhang oxygenvacancyinducedstrengtheningandtougheninginknanbo3basedpiezoceramicsrevealedviananoindentation
AT binyang oxygenvacancyinducedstrengtheningandtougheninginknanbo3basedpiezoceramicsrevealedviananoindentation
AT longyuchen oxygenvacancyinducedstrengtheningandtougheninginknanbo3basedpiezoceramicsrevealedviananoindentation
AT zaolizhang oxygenvacancyinducedstrengtheningandtougheninginknanbo3basedpiezoceramicsrevealedviananoindentation
AT jinmingguo oxygenvacancyinducedstrengtheningandtougheninginknanbo3basedpiezoceramicsrevealedviananoindentation