Wang, Xiaomei ; Liu, Xiaowei ; Li, Yingwei ; Fang, Xufei (2023)
Determination of the controlling parameters for dislocation
nucleation in SrTiO3: An investigation by nanoindentation.
In: Journal of the American Ceramic Society, 106 (10)
doi: 10.1111/jace.19218
Artikel, Bibliographie
Dies ist die neueste Version dieses Eintrags.
Kurzbeschreibung (Abstract)
We conduct nanoindentation to investigate dislocation nucleation in SrTiO3 (STO) single crystals with surface orientations of (0 0 1), (0 1 1), and (1 1 1) with loading/unloading rates of 25, 250, and 2500 μN/s. Results reveal that the critical loads (Pc) at which “pop-in” event occurs depend strongly on surface orientations, but slightly related to loading rate. Based on Pc, the critical shear stress that triggers dislocation nucleation was determined by extracting the maximum resolved shear stress (τmax) along the slip systems of STOusing the Hertzian solution. The dislocation activation shear stress (τa) was determined by averaging τmax. The determined τa is 9.0–12.0 GPa, close to the shear strength (∼G/2π) of STO, indicating that homogeneous dislocation nucleation dominates the pop-in events. The consistency of the determined τa demonstrates that the frameworks for nanoindentation pop-in analysis established for metals can be extended to ceramics, whereas the influence of the limited slip systems should be taken into consideration. Additionally, we estimated the activation volume and the activation energy via the statisticalmodel proposed by Schuh et al. The small values of the determined activation volume (0.6–9.8 Å3) and the activation energy (0.13–0.70 eV) indicate that the dislocation nucleation possibly begins from a single-atom migration and local point defects may participate in the dislocation nucleation process. That is, heterogeneous nucleation may exist initially but the homogeneous dislocation nucleation dominates the pop-in events.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2023 |
| Autor(en): | Wang, Xiaomei ; Liu, Xiaowei ; Li, Yingwei ; Fang, Xufei |
| Art des Eintrags: | Bibliographie |
| Titel: | Determination of the controlling parameters for dislocation nucleation in SrTiO3: An investigation by nanoindentation |
| Sprache: | Englisch |
| Publikationsjahr: | 14 August 2023 |
| Ort: | Oxford |
| Verlag: | Wiley-Blackwell |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Journal of the American Ceramic Society |
| Jahrgang/Volume einer Zeitschrift: | 106 |
| (Heft-)Nummer: | 10 |
| DOI: | 10.1111/jace.19218 |
| Zugehörige Links: | |
| Kurzbeschreibung (Abstract): | We conduct nanoindentation to investigate dislocation nucleation in SrTiO3 (STO) single crystals with surface orientations of (0 0 1), (0 1 1), and (1 1 1) with loading/unloading rates of 25, 250, and 2500 μN/s. Results reveal that the critical loads (Pc) at which “pop-in” event occurs depend strongly on surface orientations, but slightly related to loading rate. Based on Pc, the critical shear stress that triggers dislocation nucleation was determined by extracting the maximum resolved shear stress (τmax) along the slip systems of STOusing the Hertzian solution. The dislocation activation shear stress (τa) was determined by averaging τmax. The determined τa is 9.0–12.0 GPa, close to the shear strength (∼G/2π) of STO, indicating that homogeneous dislocation nucleation dominates the pop-in events. The consistency of the determined τa demonstrates that the frameworks for nanoindentation pop-in analysis established for metals can be extended to ceramics, whereas the influence of the limited slip systems should be taken into consideration. Additionally, we estimated the activation volume and the activation energy via the statisticalmodel proposed by Schuh et al. The small values of the determined activation volume (0.6–9.8 Å3) and the activation energy (0.13–0.70 eV) indicate that the dislocation nucleation possibly begins from a single-atom migration and local point defects may participate in the dislocation nucleation process. That is, heterogeneous nucleation may exist initially but the homogeneous dislocation nucleation dominates the pop-in events. |
| Freie Schlagworte: | activation energy, activation volume, dislocation nucleation, nanoindentation pop-in, strontium titanate |
| Zusätzliche Informationen: | This article also appears in: Editor’s Choice JACerS 2023 |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Nichtmetallisch-Anorganische Werkstoffe |
| Hinterlegungsdatum: | 15 Aug 2023 07:44 |
| Letzte Änderung: | 19 Jul 2024 10:48 |
| PPN: | 510630812 |
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| Suche nach Titel in: | TUfind oder in Google |
Verfügbare Versionen dieses Eintrags
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Determination of the controlling parameters for dislocation nucleation in SrTiO₃: An investigation by nanoindentation. (deposited 07 Nov 2023 12:30)
- Determination of the controlling parameters for dislocation nucleation in SrTiO3: An investigation by nanoindentation. (deposited 15 Aug 2023 07:44) [Gegenwärtig angezeigt]
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