Dislocation-point defect interaction on plasticity across the length scale in SrTiO3

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Hauptverfasser: Okafor, Chukwudalu, Takahara, Kohei, Korneychuk, Svetlana, Huck, Isabel, Bruns, Sebastian, Li, Ruoqi, Li, Yan, Durst, Karsten, Nakamura, Atsutomo, Fang, Xufei
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Veröffentlicht: 2025
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author Okafor, Chukwudalu
Takahara, Kohei
Korneychuk, Svetlana
Huck, Isabel
Bruns, Sebastian
Li, Ruoqi
Li, Yan
Durst, Karsten
Nakamura, Atsutomo
Fang, Xufei
author_facet Okafor, Chukwudalu
Takahara, Kohei
Korneychuk, Svetlana
Huck, Isabel
Bruns, Sebastian
Li, Ruoqi
Li, Yan
Durst, Karsten
Nakamura, Atsutomo
Fang, Xufei
contents Point defect engineering is widely used to tailor the electronic and transport properties of complex oxides, yet its influence on dislocation plasticity remains poorly understood. Here, we establish how donor (Nb) doping modifies dislocation nucleation, multiplication, and mobility in single-crystal SrTiO3 by bridging nano-, meso-, and macroscale deformation. Using a combinatorial approach involving nanoindentation, cyclic Brinell indentation, and bulk uniaxial compression, we show that 0.5 wt% Nb doping consistently suppresses room-temperature plasticity. Nanoindentation reveals increased pop-in stresses, increased lattice friction stress, and reduced creep rates, indicating inhibited dislocation nucleation and motion with Nb doping. Mesoscale Brinell indentation exhibits discrete, widely spaced slip traces reflecting more difficult dislocation multiplication. Bulk uniaxial compression confirms ~50% higher yield stress in Nb-doped (0.5 wt%) SrTiO3 samples. Comparison with Fe-doped SrTiO3 (equivalent doping concentration) isolates the role of defect chemistry: oxygen vacancies promote incipient plasticity, whereas Sr vacancies dominate in Nb-doped SrTiO3, strongly hindering dislocation motion. This length-scale bridging approach consistently reveals suppressed dislocation nucleation, multiplication, and motion in the 0.5 wt% Nb-doped samples. These insights underline the importance of dislocation-defect chemistry on the mechanical behavior of functional oxides.
format Preprint
id arxiv_https___arxiv_org_abs_2510_18620
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Dislocation-point defect interaction on plasticity across the length scale in SrTiO3
Okafor, Chukwudalu
Takahara, Kohei
Korneychuk, Svetlana
Huck, Isabel
Bruns, Sebastian
Li, Ruoqi
Li, Yan
Durst, Karsten
Nakamura, Atsutomo
Fang, Xufei
Materials Science
Point defect engineering is widely used to tailor the electronic and transport properties of complex oxides, yet its influence on dislocation plasticity remains poorly understood. Here, we establish how donor (Nb) doping modifies dislocation nucleation, multiplication, and mobility in single-crystal SrTiO3 by bridging nano-, meso-, and macroscale deformation. Using a combinatorial approach involving nanoindentation, cyclic Brinell indentation, and bulk uniaxial compression, we show that 0.5 wt% Nb doping consistently suppresses room-temperature plasticity. Nanoindentation reveals increased pop-in stresses, increased lattice friction stress, and reduced creep rates, indicating inhibited dislocation nucleation and motion with Nb doping. Mesoscale Brinell indentation exhibits discrete, widely spaced slip traces reflecting more difficult dislocation multiplication. Bulk uniaxial compression confirms ~50% higher yield stress in Nb-doped (0.5 wt%) SrTiO3 samples. Comparison with Fe-doped SrTiO3 (equivalent doping concentration) isolates the role of defect chemistry: oxygen vacancies promote incipient plasticity, whereas Sr vacancies dominate in Nb-doped SrTiO3, strongly hindering dislocation motion. This length-scale bridging approach consistently reveals suppressed dislocation nucleation, multiplication, and motion in the 0.5 wt% Nb-doped samples. These insights underline the importance of dislocation-defect chemistry on the mechanical behavior of functional oxides.
title Dislocation-point defect interaction on plasticity across the length scale in SrTiO3
topic Materials Science
url https://arxiv.org/abs/2510.18620