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Updated: May 20, 2026
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In Situ Transmission Electron Microscopy with Biasing and Fabrication of Asymmetric Crossbars Based on Mixed-Phased a-VOx
Published on: May 13, 2020
Ionically-mediated electromechanical hysteresis in transition metal oxides
Yunseok Kim1, Anna N Morozovska, Amit Kumar
1The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA. ykim943@gmail.com
ACS Nano
|August 1, 2012
Summary
Scanning probe microscopy reveals nanoscale electromechanical activity in paraelectric titanium dioxide and strontium titanate thin films. Ionic dynamics can induce ferroelectric behavior, explaining phenomena in these transition metal oxides.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Perovskite oxides like TiO(2) and SrTiO(3) exhibit complex electromechanical responses.
- Understanding ferroelectric-like behavior in centrosymmetric materials is crucial for advanced electronic applications.
Purpose of the Study:
- To investigate nanoscale electromechanical activity and polarization states in paraelectric TiO(2) and SrTiO(3) thin films.
- To analyze the coupling between ionic dynamics and incipient ferroelectricity using Landau-Ginzburg-Devonshire theory.
- To identify the origins of electromechanical coupling and explain ferroelectric-like phenomena.
Main Methods:
- Utilizing scanning probe microscopy to observe nanoscale electromechanical activity, remanent polarization, and hysteresis loops.
- Applying extended Landau-Ginzburg-Devonshire (LGD) theory to model the coupling between ionic dynamics and ferroelectricity.
- Analyzing ionic transport mechanisms and their influence on polarization states.
Main Results:
- Observed nanoscale electromechanical activity and remanent polarization in paraelectric TiO(2) and SrTiO(3) thin films.
- Identified ionic dynamics, surface-charge induced electrostriction, and ionically induced ferroelectricity as key contributors to electromechanical coupling.
- Demonstrated that ionic contributions can effectively induce ferroelectricity by altering LGD expansion coefficients.
Conclusions:
- Ionic dynamics play a critical role in inducing ferroelectric-like behavior in centrosymmetric transition metal oxides.
- The lifetime of ionically induced ferroelectric states is governed by mobile ion transport, exceeding typical polarization switching times.
- These findings offer a mechanistic explanation for observed ferroelectric properties in materials not exhibiting intrinsic ferroelectricity.
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