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Alexander Tagantsev

Cette personne a quitté l’EPFL

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Publications associées (129)

Page 3 sur 7

Pseudoferroelectricity: A possible scenario for doped ZnO

Alexander Tagantsev

A phenomenological Landau-theory model, where a crystal on cooling from a state with polar symmetry exhibits a maximum of dielectric permittivity and polarization-field hysteresis loops, is offered. The model is equivalent to that of a true ferroelectric i ...

AIP American Institute of Physics2008

Flexoelectric effect in finite samples

Alexander Tagantsev

Static flexoelectric effect in a finite sample of a solid is addressed in terms of phenomenological theory for the case of a thin plate subjected to bending. It has been shown that despite an explicit asymmetry inherent to the bulk constitutive electromech ...

American Institute of Physics2012

Electrical tuning of dc bias induced acoustic resonances in paraelectric thin films

Alexander Tagantsev, Nava Setter, Andreas Nöth

A theoretical model for the dc bias dependence of induced acoustic resonances in paraelectric materials is presented. The field dependent piezoelectric constitutive equations were derived from the Landau free energy expansion with respect to the ferroelect ...

2008

Structure and pressure-induced ferroelectric phase transition in antiphase domain boundaries of strontium titanate from first principles

Alexander Tagantsev, Nava Setter, Alexander Kvasov

In this work, using zero kelvin ab initio calculations, we revisit the structure and ferroelectric phase transition in antiphase domain boundaries (APBs) in SrTiO3 (STO), which has been previously addressed in terms of a phenomenological approach. We confi ...

Amer Physical Soc2016

Structural phase transitions and electronic phenomena at 180-degree domain walls in rhombohedral BaTiO3

Alexander Tagantsev, Nava Setter, Petr Yudin

The structure and electronic phenomena at the 180-degree domain wall in the rhombohedral phase of BaTiO3 are described using Landau-Ginzburg-Devonshire theory. Dependent on the wall orientation, two types of domain wall behaviors are identified. The low-en ...

American Physical Society2013

Evidence for dielectric aging due to progressive 180 degrees domain wall pinning in polydomain Pb(Zr0.45Ti0.55)O-3 thin films

Alexander Tagantsev, Nava Setter, Dragan Damjanovic, Igor Stolichnov

An evidence that the dielectric aging in the polydomain Pb(Zr0.45Ti0.55)O-3 thin films is controlled by progressive pinning of 180 degrees domain walls is presented. To provide such a conclusion, we use a general method, which is based on the study of the ...

2009

Susceptibility anomaly in films with bilinear coupling between order parameter and strain

Alexander Tagantsev

The dielectric response of a ferroelectric film with bilinear coupling between order parameter and strain is theoretically addressed. An exact solution for the total (lattice and domain contributions) dielectric permittivity of the system for the case wher ...

2005

Optimal optomechanical cavity setups with highly reflecting membranes

Alexander Tagantsev

Highly reflecting mechanically compliant membranes based on photonic-crystal patterns have recently gained increasing attention within cavity optomechanics due to their prospects of reaching high coupling rates in membrane-in-the-middle experiments. Here, ...

2024

Single-domain (110) PbTiO3 thin films: Thermodynamic theory and experiments

Nava Setter, Alexander Tagantsev, Mahamudu Mtebwa

We report the thermodynamic potential for single-domain (110) thin films epitaxially grown on dissimilar cubic substrates. Using different sets of paraelectric phase elastic compliance coefficients of PbTiO3 single crystal, calculated from the experimental ...

Amer Physical Soc2016

Effective-surface-energy approach for size effects in ferroics

Alexander Tagantsev, Nava Setter, Jin Wang

We present a simple approach enabling analytical treatments of size effects in ferroelectric samples of complicated shapes for the cases where long-range depolarizing effects are not involved. The key element of the approach is the presentation of the ener ...

American Physical Society2015

Synthesis, structure, and electrical behavior of Sr4Bi4Ti7O24

Alexander Tagantsev, Yihan Jia

An n=7 Aurivillius phase, Sr4Bi4Ti7O24, with c=6.44 nm, was synthesized as an epitaxial (001)-oriented film. This phase and its purity were confirmed by x-ray diffraction and transmission electron microscopy. The material is ferroelectric, with a P-r=5.3 m ...

American Institute of Physics2010

Ferroelectric charged domain walls in an applied electric field

Nava Setter, Alexander Tagantsev, Maxim Gureev

The interaction of electric field with charged domain walls in ferroelectrics is theoretically addressed. Ageneral expression for the force acting per unit area of a charged domain wall carrying free charge is derived. It is shown that, in proper ferroelec ...

American Physical Society2012

Finite-temperature flexoelectricity in ferroelectric thin films from first principles

Alexander Tagantsev

A first-principles-based effective Hamiltonian technique is developed to study flexoelectricity in (Ba0.5Sr0.5)TiO3 thin films of different thicknesses in their paraelectric phase. The magnitude as well as sign of individual components of the flexoelectric ...

2012

Suppressed polar distortion with enhanced Curie temperature in in-plane 90 degrees-domain structure of a-axis oriented PbTiO3 Film

Alexander Tagantsev

PbTiO3 thin films were epitaxially grown on (001) KTaO3 single crystal substrates by metalorganic chemical vapor deposition. The coherent epitaxial growth introduced a large in-plane tensile strain to the PbTiO3 film. This tensile strain increased T-C and ...

Amer Inst Physics2015

Landau Expansion for Ferroelectrics: Which Variable to Use?

Alexander Tagantsev

The problem of the choice of the order parameter of the Landau expansion of proper ferroelectrics is discussed. The expansion with respect to the (i) electric displacement, (ii) polarization, (iii) ferroelectric contribution to the polarization, (iv) "orde ...

2008

Direct Observation of Capacitor Switching Using Planar Electrodes

Alexander Tagantsev

Ferroelectric polarization switching in epitaxial (110) BiFeO3 films is studied using piezoresponse force microscopy of a model in-plane capacitor structure. The electrode orientation is chosen such that only two active domain variants exist. Studies of th ...

Wiley-Blackwell2010

Theoretical estimation of the linear electro-optic effect in compressively strained c-domain (Ba, Sr)TiO3 thin films using a phenomenological thermodynamic model

Nava Setter, Alexander Tagantsev

The influence of compressive strain on the linear electro-optic (EO) effect in c-domain (BaxSr1-x)TiO3 (BST) thin films was theoretically investigated using a phenomenological thermodynamic model. We considered that the c-domain BST thin films were grown o ...

CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI2019

Negative-pressure-induced enhancement in a freestanding ferroelectric

Nava Setter, Alexander Tagantsev, Marco Cantoni, Silviu Cosmin Sandu, Tomas Sluka, Jin Wang, Alexander Kvasov

Ferroelectrics are widespread in technology(1), being used in electronics and communications(2), medical diagnostics and industrial automation. However, extension of their operational temperature range and useful properties is desired(3-5). Recent developm ...

Nature Publishing Group2015

Ionic polarizability of conductive metal oxides and critical thickness for ferroelectricity in BaTiO3

Nava Setter, Alexander Tagantsev, Guido Gerra

We report a first-principles investigation of ultrathin BaTiO3 films with SrRuO3 electrodes. We find that the ionic relaxations in the metal-oxide electrode play a crucial role in stabilizing the ferroelectric phase. Comparison with frozen-phonon calculati ...

2006

Quasi-Debye microwave loss as an intrinsic limitation of microwave performance of tunable components based on SrTiO3 and BaxSr1-xTiO3 ferroelectrics

Nava Setter, Alexander Tagantsev, Konstantin Astafiev

A model of the quasi-Debye loss mechanism in SrTiO3 and Ba0.6Sr0.4TiO3 perovskite ferroelectrics at microwave frequencies is presented. The field dependence and the size of the field-induced quasi-Debye loss contribution in SrTiO3 and Ba0.6Sr0.4TiO3 system ...

2005