Phase-field modeling of chemical control of polarization stability and switching dynamics in ferroelectric thin films

Cao, Ye; Kalinin, Sergei V.

doi:10.1103/physrevb.94.235444

Cited by 25 publications

(10 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here is the oxygen partial pressure excess (relative to atmospheric pressure ), is the number of surface ions created per oxygen molecule, is the free energy of the surface ion p electrode exposed to ions in a solution [70,71,78]. Equations (4) can be incorporated in the numerical or phase-field formalism [79]. We further note that the developed solutions are insensitive to the specific details of the charge compensation process, and are sensitive only to the thermodynamic parameters of corresponding reactions.…”

Section: B Polarization Screening By Surface Ionsmentioning

confidence: 99%

Ferroionic states in ferroelectric thin films

et al. 2017

Self Cite

View full text Add to dashboard Cite

The electric coupling between surface ions and bulk ferroelectricity gives rise to a continuum of mixed states in ferroelectric thin films, exquisitely sensitive to temperature and external factors, such as applied voltage and oxygen pressure. Here we develop the comprehensive analytical description of these coupled ferroelectric and ionic ("ferroionic") states by combining the Ginzburg-Landau-Devonshire description of the ferroelectric properties of the film with Langmuir adsorption model for the electrochemical reaction at the film surface. We explore the thermodynamic and kinetic characteristics of the ferroionic states as a function of temperature, film thickness, and external electric potential. These studies provide a new insight into mesoscopic properties of ferroelectric thin films, whose surface is exposed to chemical environment as screening charges supplier.

show abstract

Section: B Polarization Screening By Surface Ionsmentioning

confidence: 99%

Ferroionic states in ferroelectric thin films

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…83 In classic phase-field model, the in which L is the film thickness and app V denotes the applied electric bias. These represent the situation when the polarization bound charges at the top/bottom surface are fully screened by the metal electrode at fixed bias ( app V ).…”

Section: (#/Mol)mentioning

confidence: 99%

“…83,84 The electrochemical potential of the screening surface ions is also subjected to the mechanical pressure at the tip-surface junction. The shift of formation energy ( G  ) by the tip pressure can be estimated to be PV  , where P is the applied pressure and V  is the difference in ionic volume.…”

Section: (#/Mol)mentioning

confidence: 99%

Pressure-induced switching in ferroelectrics: Phase-field modeling, electrochemistry, flexoelectric effect, and bulk vacancy dynamics

2017

Self Cite

View full text Add to dashboard Cite

United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for the United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). Pressure-induced polarization switching in ferroelectric thin films has emerged as a powerful method for domain patterning, allowing to create predefined domain patterns on free surfaces and under thin conductive top electrodes. However, the mechanisms for pressure induced polarization switching in ferroelectrics remain highly controversial, with flexoelectricity, polarization rotation and suppression, and bulk and surface electrochemical processes all being potentially relevant. Here we classify possible pressure induced switching mechanisms, perform elementary estimates, and study in depth using phase-field modelling. We show that magnitudes of these effects are remarkably close, and give rise to complex switching diagrams as a function of pressure and film thickness with non-trivial topology or switchable and non-switchable regions.

show abstract

“…[1][2][3][4][5] In this respect, adsorbed water from the environment has long been recognized as playing a crucial role in electrostatic screening under atmospheric conditions due to its polar nature and ionic conductivity, and the associated screening dynamics have been studied as a function of humidity 6,7 and temperature, [8][9][10] leading to the development of a full thermodynamic theory of the screening mechanisms. 11 However, few studies and ab initio modeling have considered the capacity of water molecules to dissociate and participate in redox chemical reactions at ferroelectric surfaces, [12][13][14][15][16] which would be expected to provide a large additional screening contribution, 17,18 in particular on highly reactive perovskite oxides. 19,20 Moreover, surface chemistry is not only important for the stabilization of ferroelectric surfaces, 21 but in fact polarization switching kinetics are intrinsically coupled to surface electrochemical phenomena.…”

Section: Introductionmentioning

confidence: 99%