Eliseev, Eugene A. ; Vorotiahin, Ivan S. ; Fomichov, Yevhen M. ; Glinchuk, Maya D. ; Kalinin, Sergei V. ; Genenko, Yuri A. ; Morozovska, Anna N. (2018)
Defect-driven flexochemical coupling in thin ferroelectric films.
In: Physical Review B, 97 (2)
doi: 10.1103/PhysRevB.97.024102
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
Using the Landau-Ginzburg-Devonshire theory, we considered the impact of the flexoelectrochemical coupling on the size effects in polar properties and phase transitions of thin ferroelectric films with a layer of elastic defects. We investigated a typical case, when defects fill a thin layer below the top film surface with a constant concentration creating an additional gradient of elastic fields. The defective surface of the film is not covered with an electrode, but instead with an ultrathin layer of ambient screening charges, characterized by a surface screening length. Obtained results revealed an unexpectedly strong effect of the joint action of Vegard stresses and flexoelectric effect (shortly flexochemical coupling) on the ferroelectric transition temperature, distribution of the spontaneous polarization and elastic fields, domain wall structure and period in thin PbTiO3 films containing a layer of elastic defects. A nontrivial result is the persistence of ferroelectricity at film thicknesses below 4 nm, temperatures lower than 350 K, and relatively high surface screening length (∼0.1nm). The origin of this phenomenon is the flexoelectric coupling leading to the rebuilding of the domain structure in the film (namely the cross-over from c-domain stripes to a-type closure domains) when its thickness decreases below 4 nm. The ferroelectricity persistence is facilitated by negative Vegard effect. For positive Vegard effect, thicker films exhibit the appearance of pronounced maxima on the thickness dependence of the transition temperature, whose position and height can be controlled by the defect type and concentration. The revealed features may have important implications for miniaturization of ferroelectric-based devices.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2018 |
| Autor(en): | Eliseev, Eugene A. ; Vorotiahin, Ivan S. ; Fomichov, Yevhen M. ; Glinchuk, Maya D. ; Kalinin, Sergei V. ; Genenko, Yuri A. ; Morozovska, Anna N. |
| Art des Eintrags: | Bibliographie |
| Titel: | Defect-driven flexochemical coupling in thin ferroelectric films |
| Sprache: | Englisch |
| Publikationsjahr: | 5 Januar 2018 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Physical Review B |
| Jahrgang/Volume einer Zeitschrift: | 97 |
| (Heft-)Nummer: | 2 |
| DOI: | 10.1103/PhysRevB.97.024102 |
| URL / URN: | https://doi.org/10.1103/PhysRevB.97.024102 |
| Kurzbeschreibung (Abstract): | Using the Landau-Ginzburg-Devonshire theory, we considered the impact of the flexoelectrochemical coupling on the size effects in polar properties and phase transitions of thin ferroelectric films with a layer of elastic defects. We investigated a typical case, when defects fill a thin layer below the top film surface with a constant concentration creating an additional gradient of elastic fields. The defective surface of the film is not covered with an electrode, but instead with an ultrathin layer of ambient screening charges, characterized by a surface screening length. Obtained results revealed an unexpectedly strong effect of the joint action of Vegard stresses and flexoelectric effect (shortly flexochemical coupling) on the ferroelectric transition temperature, distribution of the spontaneous polarization and elastic fields, domain wall structure and period in thin PbTiO3 films containing a layer of elastic defects. A nontrivial result is the persistence of ferroelectricity at film thicknesses below 4 nm, temperatures lower than 350 K, and relatively high surface screening length (∼0.1nm). The origin of this phenomenon is the flexoelectric coupling leading to the rebuilding of the domain structure in the film (namely the cross-over from c-domain stripes to a-type closure domains) when its thickness decreases below 4 nm. The ferroelectricity persistence is facilitated by negative Vegard effect. For positive Vegard effect, thicker films exhibit the appearance of pronounced maxima on the thickness dependence of the transition temperature, whose position and height can be controlled by the defect type and concentration. The revealed features may have important implications for miniaturization of ferroelectric-based devices. |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Materialmodellierung 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften |
| Hinterlegungsdatum: | 30 Jan 2018 09:27 |
| Letzte Änderung: | 30 Jan 2018 09:27 |
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