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Abstract The unique nonlinear dielectric properties of antiferroelectric (AFE) oxides are promising for advancements in solid state supercapacitor, actuator, and memory technologies. AFE behavior in high‐k ZrO2is of particular technological interest, but the origin of antiferroelectricity in ZrO2remains questionable. The theory of reversible electric field‐induced phase transitions between the nonpolar P42/nmc tetragonal phase and the polarPca21orthorhombic phase is experimentally tested with local structural and electromechanical characterization of AFE ZrO2thin films. Piezoresponse force microscopy identifies signature evidence of a field‐induced phase transition. A significant size effect in AFE ZrO2is experimentally observed as film thickness is scaled down from 14.7 to 4.3 nm. The size effect is explained by modifications to the phase transition energy barrier heights ranging from 0.6 to 7.6 meV f.u−1depending on crystallite size and in‐plane compressive strain with decreasing ZrO2film thickness. Using the size effect, it is possible to double the energy storage density in ZrO2from 20 J cm−3to greater than 40 J cm−3, thus highlighting a feasible route for superior performance in AFE fluorite supercapacitors.
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Antiferroelectric negative capacitance from a structural phase transition in zirconia
Abstract Crystalline materials with broken inversion symmetry can exhibit a spontaneous electric polarization, which originates from a microscopic electric dipole moment. Long-range polar or anti-polar order of such permanent dipoles gives rise to ferroelectricity or antiferroelectricity, respectively. However, the recently discovered antiferroelectrics of fluorite structure (HfO2and ZrO2) are different: A non-polar phase transforms into a polar phase by spontaneous inversion symmetry breaking upon the application of an electric field. Here, we show that this structural transition in antiferroelectric ZrO2gives rise to a negative capacitance, which is promising for overcoming the fundamental limits of energy efficiency in electronics. Our findings provide insight into the thermodynamically forbidden region of the antiferroelectric transition in ZrO2and extend the concept of negative capacitance beyond ferroelectricity. This shows that negative capacitance is a more general phenomenon than previously thought and can be expected in a much broader range of materials exhibiting structural phase transitions.
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- Award ID(s):
- 2047880
- PAR ID:
- 10363853
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Publisher / Repository:
- Nature Publishing Group
- Date Published:
- Journal Name:
- Nature Communications
- Volume:
- 13
- Issue:
- 1
- ISSN:
- 2041-1723
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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