This title appears in the Scientific Report :
2020
Please use the identifier:
http://dx.doi.org/10.1038/s41524-020-00418-z in citations.
Please use the identifier: http://hdl.handle.net/2128/26470 in citations.
Electrochemical drag effect on grain boundary motion in ionic ceramics
Electrochemical drag effect on grain boundary motion in ionic ceramics
The effects of drag imposed by extrinsic ionic species and point defects on the grain boundary motion of ionic polycrystalline ceramics were quantified for the generality of electrical, chemical, or structural driving forces. In the absence of, or for small driving forces, the extended electrochemic...
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Personal Name(s): | Vikrant, K. S. N. |
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Rheinheimer, Wolfgang / García, R. Edwin (Corresponding author) | |
Contributing Institute: |
Werkstoffsynthese und Herstellungsverfahren; IEK-1 |
Published in: | npj computational materials, 6 (2020) 1, S. 165 |
Imprint: |
London
Nature Publ. Group
2020
|
DOI: |
10.1038/s41524-020-00418-z |
Document Type: |
Journal Article |
Research Program: |
ohne Topic |
Link: |
OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/26470 in citations.
The effects of drag imposed by extrinsic ionic species and point defects on the grain boundary motion of ionic polycrystalline ceramics were quantified for the generality of electrical, chemical, or structural driving forces. In the absence of, or for small driving forces, the extended electrochemical grain boundary remains pinned and symmetrically distributed about the structural interface. As the grain boundary begins to move, charged defects accumulate unsymmetrically about the structural grain boundary core. Above the critical driving force for motion, grain boundaries progressively shed individual ionic species, from heavier to lighter, until they display no interfacial electrostatic charge and zero Schottky potential. Ionic p–n junction moving grain boundaries that induce a finite electrostatic potential difference across entire grains are identified for high velocity grains. The developed theory is demonstrated for Fe-doped SrTiO3. The increase in average Fe concentration and grain boundary crystallographic misorientation enhances grain boundary core segregation and results in thick space charge layers, which leads to a stronger drag force that reduces the velocity of the interface. The developed theory sets the stage to assess the effects of externally applied fields such as temperature, electromagnetic fields, and chemical stimuli to control the grain growth for developing textured, oriented microstructures desirable for a wide range of applications. |