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Direct observation of room-temperature out-of-plane ferroelectricity and tunneling electroresistance at the two-dimensional limit
- Source :
- Nature Communications, Vol 9, Iss 1, Pp 1-8 (2018), Nature Communications
- Publication Year :
- 2018
- Publisher :
- Nature Portfolio, 2018.
-
Abstract
- Out-of-plane ferroelectricity with a high transition temperature in nanometer-scale films is required to miniaturize electronic devices. Direct visualization of stable ferroelectric polarization and its switching behavior in atomically thick films is critical for achieving this goal. Here, ferroelectric order at room temperature in the two-dimensional limit is demonstrated in tetragonal BiFeO3 ultrathin films. Using aberration-corrected scanning transmission electron microscopy, we directly observed robust out-of-plane spontaneous polarization in one-unit-cell-thick BiFeO3 films. High-resolution piezoresponse force microscopy measurements show that the polarization is stable and switchable, whereas a tunneling electroresistance effect of up to 370% is achieved in BiFeO3 films. Based on first-principles calculations and Kelvin probe force microscopy measurements, we explain the mechanism of polarization stabilization by the ionic displacements in oxide electrode and the surface charges. Our results indicate that critical thickness for ferroelectricity in the BiFeO3 film is virtually absent, making it a promising candidate for high-density nonvolatile memories.<br />High temperature perpendicular ferroelectricity in nano thin films is crucial for miniaturization of electronic devices. Here the authors show the presence of stable and switchable out-of-plane ferroelectricity in tetragonal BiFeO3 thin films at the two-dimensional limit and 370% tunneling electroresistance in ferroelectric tunnel junctions.
- Subjects :
- Kelvin probe force microscope
Multidisciplinary
Materials science
Condensed matter physics
Transition temperature
Science
General Physics and Astronomy
02 engineering and technology
General Chemistry
021001 nanoscience & nanotechnology
Polarization (waves)
01 natural sciences
Ferroelectricity
General Biochemistry, Genetics and Molecular Biology
Article
Tetragonal crystal system
Piezoresponse force microscopy
0103 physical sciences
Scanning transmission electron microscopy
Microscopy
lcsh:Q
010306 general physics
0210 nano-technology
lcsh:Science
Subjects
Details
- Language :
- English
- ISSN :
- 20411723
- Volume :
- 9
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Nature Communications
- Accession number :
- edsair.doi.dedup.....4346993dc6ee55b51802a54f0a0f0f42