Publications associées à Impact of Strain Effects on the Stability of Ising Walls in Ferroelectrics

Chiral magnetohydrodynamics with zero total chirality

We study the evolution of magnetic fields coupled with chiral fermion asymmetry in the framework of chiral magnetohydrodynamics with zero initial total chirality. The initial magnetic field has a turbulent spectrum peaking at a certain characteristic scale ...

American Physical Society2023

Ultrahigh Electrostrictive Effect in Lead-Free Ferroelectric Ceramics Via Texture Engineering

Dragan Damjanovic, Li Jin, Yuan Sun

The electrostrictive effect, which induces strain in ferroelectric ceramics, offers distinct advantages over its piezoelectric counterpart for high-precision actuator applications, including anhysteretic behavior even at high frequencies, rapid reaction ti ...

Amer Chemical Soc2023

Intrinsic-Strain Engineering by Dislocation Imprint in Bulk Ferroelectrics

Dragan Damjanovic, Fangping Zhuo

We report an intrinsic strain engineering, akin to thin filmlike approaches, via irreversible hightemperature plastic deformation of a tetragonal ferroelectric single-crystal BaTiO3. Dislocations wellaligned along the [001] axis and associated strain field ...

AMER PHYSICAL SOC2023

Printed degradable piezoelectric microsystems: From ink formulation to device fabrication and characterization

Morgan Mc Kay Monroe

As the world moves further and further into the semiconductor era, the amount of waste generated from electronics ("e-waste") is increasing rapidly and unsustainably. Of particular note, alternatives to lead-based piezoelectric materials must be establishe ...

EPFL2023

Hard X-ray helical dichroism of disordered molecular media

Majed Chergui, Jérôme Lacour, Christian David, Giulia Fulvia Mancini, Malte Oppermann, Dominik Kinschel, Oliviero Cannelli, Camila Bacellar Cases Da Silveira

Chirality is a structural property of molecules lacking mirror symmetry that has strong implications in diverse fields, ranging from life sciences to materials science. Chirality-sensitive spectroscopic methods, such as circular dichroism, exhibit weak sig ...

Nature Publishing Group2022

Nonlinear electro-mechanical coupling and thermally stimulated currents in relaxor ferroelectrics

Lukas Riemer

In this work, the emergence of polarization and electro-mechanical coupling in Pb(Mg1/3Nb2/3)O3 and Pb(Mg1/3Nb2/3)O3 â PbTiO3 was investigated by means of thermally stimulated current, and nonlinear dielectric and electro-mechanical measurements. The pre ...

EPFL2022

Optical metasurfaces: synthesis, nanofabrication, and colorful applications

Hsiang-Chu Wang

In this thesis, we mainly utilize silver to construct the meta-atoms. Although suffering from easily oxidized, its excellent lossless property throughout the visible range makes it suitable for study. When preserved properly, silver-made metasurfaces can s ...

EPFL2022

Observation of a singular Weyl point surrounded by charged nodal walls in PtGa

Oleg Yazyev, Jan Hugo Dil, Quansheng Wu, Shengnan Zhang

Constrained by the Nielsen-Ninomiya no-go theorem, in all so-far experimentally determined Weyl semimetals (WSMs) the Weyl points (WPs) always appear in pairs in the momentum space with no exception. As a consequence, Fermi arcs occur on surfaces which con ...

Nature Research2021

Control of a polar order via magnetic field in a vector-chiral magnet

Helmuth Berger

Vector-chiral (VC) antiferromagnetism is a spiral-like ordering of spins which may allow ferroelectricity to occur due to loss of space inversion symmetry. In this Letter we report direct experimental observation of ferroelectricity in the VC phase of beta ...

AMER PHYSICAL SOC2021

Discrete metal nanoparticles with plasmonic chirality

Jijun He

From a geometrical perspective, a chiral object does not have mirror planes or inversion symmetry. It exhibits the same physical properties as its mirror image (enantiomer), except for the chiroptical activity, which is often the opposite. Recent advanceme ...

Royal Society of Chemistry2021

Absolute Structure from Scanning Electron Microscopy

Philip Johannes Walter Moll

The absence of centrosymmetry in chiral and polar crystal structures is the reason for many technical relevant physical properties like optical birefringence or ferroelectricity. Other chirality related properties that are actually intensively investigated ...

Nature Research2020

Correlation between Optical Activity and the Helical Molecular Orbitals of Allene and Cumulenes

Anne-Clémence Corminboeuf, Marc Hamilton Folkmann Garner

Helical frontier molecular orbitals (MOs) appear in disubstituted allenes and even-n cumulenes. Chiral molecules are optically active, but while these molecules are single-handed chiral, p-orbitals of both helicities are present. Here we computationally ex ...

AMER CHEMICAL SOC2020

Interface-Dominated Time-Dependent Behavior of Poled Poly(Vinylidene Fluoride–Trifluoroethylene)/Barium Titanate Composites

Dragan Damjanovic, Yves Leterrier, Véronique Michaud, Sara Dalle Vacche

Composites in which particles of ferroelectric ceramic phase are randomly dispersed in a polymeric matrix are of interest because of flexibility, conformability, and ease of processing. However, their piezoelectric properties are rather low, unless very hi ...

2020

Helical structures with switchable and hierarchical chirality

Huijuan Feng

Chirality is present as a trend of research in biological and chemical communities for it has a significant effect on physiological properties and pharmacological effects. Further, manipulating specific morphological chirality recently has emerged as a pro ...

AMER INST PHYSICS2020

A Subwavelength Microwave Bandpass Filter Based on a Chiral Waveguide

Maliheh Khatibi Moghaddam, Romain Christophe Rémy Fleury

Wave manipulation at a subwavelength scale has recently attracted significant interest, especially for low-frequency wave propagation, from acoustic to microwave devices. Recently, a few methods achieving subwavelength routing using locally resonant metama ...

IEEE Xplore2020

Individual Barkhausen Pulses of Ferroelastic Nanodomains

Dragan Damjanovic, Vasiliki Tileli, Reinis Ignatans

Ferroelectric materials, upon electric field biasing, display polarization discontinuities known as Barkhausen jumps, a subclass of a more general phenomenon known as crackling noise. Herein, we follow at the nanoscale the motion of 90 degree needle domain ...

2021

Subwavelength robust waveguiding with chiral metamaterial waveguides

Romain Christophe Rémy Fleury, Nadège Sihame Kaïna, Bakhtiyar Orazbayev

In this work, we design and experimentally demonstrate in the microwave range a robust metamaterial waveguide, which is formed at the boundary between two locally resonant chiral metamaterials with opposite chirality. We show that the interface states at s ...

IEEE2019

Dielectric Actuation Techniques at the Nanoscale: Piezoelectricity and Flexoelectricity

Kaitlin Marie Howell

Micro- and nanoelectromechanical systems (MEMS/NEMS) have long shown their potential to disrupt the established technologies. Over the past 15 years, MEMS have become fundamental components in filters, accelerometers, gyroscopes and gas sensors. MEMS are n ...

EPFL2019

Strain generation and energy-conversion mechanisms in lead-based and lead-free piezoceramics

Dragan Damjanovic

Piezoelectric ceramics generate strain through the intrinsic piezoelectric effect, the motion of ferroelectric domain walls, or through field-induced phase transitions. The enhanced piezoelectric properties observed in morphotropic solid solutions arise fr ...

2018

Chiral Waveguides for Robust Waveguiding at the Deep Subwavelength Scale

Romain Christophe Rémy Fleury, Nadège Sihame Kaïna, Bakhtiyar Orazbayev

Routing electromagnetic energy at a scale smaller than the wavelength is a highly sought functionality in a variety of applications, including compact lightweight satellite communications, slow-waves sensors, all-optical information processing, and energy ...

American Physical Society (APS)2018