Anomalous motion of charged domain walls and associated negative capacitance in copper-chlorine boracite.
Author(s)
Type
Journal Article
Abstract
During switching, the microstructure of a ferroelectric normally adapts to align internal dipoles with external electric fields. Favorably oriented dipolar regions (domains) grow at the expense of those in unfavorable orientations and this is manifested in a predictable field-induced motion of the walls that separate one domain from the next. Here, the discovery that specific charged 90°domain walls in copper-chlorine boracite move in the opposite direction to that expected, increasing the size of the domain in which polarization is anti-aligned with the applied field, is reported. Polarization-field (P-E) hysteresis loops, inferred from optical imaging, show negative gradients and non-transient negative capacitance, throughout the P-E cycle. Switching currents (generated by the relative motion between domain walls and sensing electrodes) confirm this, insofar as their signs are opposite to those expected conventionally. For any given bias, the integrated switching charge due to this anomalous wall motion is directly proportional to time, indicating that the magnitude of the negative capacitance component should be inversely related to frequency. This passes Jonscher's test for the misinterpretation of positive inductance and gives confidence that field-induced motion of these specific charged domain walls generates a measurable negative capacitance contribution to the overall dielectric response.
Date Issued
2021-04-22
Date Acceptance
2021-02-14
Citation
Advanced Materials, 2021, 33 (16), pp.1-10
ISSN
0935-9648
Publisher
Wiley
Start Page
1
End Page
10
Journal / Book Title
Advanced Materials
Volume
33
Issue
16
Copyright Statement
© 2021 The Authors. Advanced Materials published by Wiley‐VCH GmbH
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/33734520
Subjects
boracites
domain walls
negative capacitance
Publication Status
Published
Coverage Spatial
Germany
Date Publish Online
2021-03-18