Publications associées à Elastic, dielectric, and piezoelectric anomalies and Raman spectroscopy of 0.5Ba(Ti0.8Zr0.2)O3-0.5(Ba0.7Ca0.3)TiO3

Piezoelectric Properties of BiFeO3 Exposed to High Temperatures

BiFeO3 is a ferroelectric with a Curie temperature of 830 C-degrees, however, its piezoelectric performance at high temperature remains unclear. The current work reveals a disappearance/recovery of piezoelectricity in BiFeO3 at elevated temperature and upo ...

Wiley-V C H Verlag Gmbh2024

Modeling friction and wear using an adaptive discrete-continuum coupling

Manon Eugénie Voisin--Leprince

When two objects slide against each other, wear and friction occur at their interface. The accumulation of wear forms what is commonly referred to as a ``third-body''. Understanding third-body evolution has significant applications in industry, where contr ...

EPFL2024

Tailor-made Piezoelectric Elastomer Materials

Francis Owusu

Recent advancements in miniature devices with higher computational capabilities and ultralow power consumption have accelerated the development of wearable sensors, actuators, and energy harvesters everywhere. The ultimate aim of such a technological revol ...

EPFL2023

Atomic-scale Characterization of Strain and Gate effects on Two-dimensional Materials by Scanning Tunneling Microscopy

Jz -Yuan Juo

Strain is an inevitable phenomenon in two-dimensional (2D) material, regardless of whether the film is suspended or supported. Moreover, strain is known to alter the physical and chemical properties, such as the band gap, charge carrier effective masses, d ...

EPFL2023

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

Valence Orbitals Driving the Spin Dynamics in a Rare-Earth Single-Atom Magnet

Harald Brune, François Patthey, Stefano Rusponi, Marina Pivetta, Dante Philippe Sblendorio, Alberto Curcella

We combine spin-polarized scanning tunneling microscopy with quantum master equation analysis to investigate the spin dynamics of the single atom magnet Dy on graphene/Ir(111). By performing reading and writing experiments, we show that the strongly spin p ...

AMER PHYSICAL SOC2023

How to Make Elastomers Piezoelectric?

Frank Nüesch, Francis Owusu

Piezoelectrics play a significant role in modern electronics and electric devices. Thermal or mechanical stress on such materials induces a change in polarization generating an electric response, which is the sole effect of why they are so interesting. How ...

Wiley2023

Ferroelectric Effects Probed by in situ Transmission Electron Microscopy

Reinis Ignatans

Ferroelectric perovskite oxides are widely used in sensors, actuators and optical modulators and, at the same time, they show promise for implementation in future applications such as energy storage, memory and cooling devices. At the infancy of the discov ...

EPFL2022

Stretchable High Response Piezoelectric Elastomers Based on Polable Polynorbornene Fillers in a Polydimethylsiloxane Matrix

Frank Nüesch, Francis Owusu

To advance the field of piezoelectrics, it is desirable to find materials that combine high piezoelectricity with high elasticity. Applications such as self-sensors, stretchable electronics, soft robots, and energy harvesting would benefit tremendously. Ho ...

WILEY-V C H VERLAG GMBH2022

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

Relaxation time shift of Cobalt related internal friction peak in WC-Co cemented carbide

Daniele Mari, Samy Adjam, Lucas Eric Jacques Degeneve

Cemented carbides are widely used in the cutting tools industry for their mechanical properties. They are composite materials made of hard tungsten carbide grains jointed together by a ductile cobalt binder. Due to the extreme conditions of use of the tool ...

ELSEVIER SCIENCE SA2022

Disorder-induced electronic, magnetic, and optoelectronic properties of two-dimensional materials

Cheol Yeon Cheon

Technological advancement has been in cadence with material development by improving the purity of single crystals and, at the same time, controlling their imperfections. These capabilities have been especially vital for developing new technolo-gies based ...

EPFL2022

Strengthening mechanisms in dilute and random solid solution high-entropy BCC alloys

Alireza Ghafarollahi

Tuning the mechanical properties of metals, including strength, through adjusting the type and/or concentration of added solute elements, has been recognized as an effective way to design and produce materials with desired or optimized mechanical propertie ...

EPFL2022

Piezoelectric suspended microchannel resonators

Damien Maillard

The objective of this PhD thesis is the development of a microfluidic platform for the real-time measurements of the mechanical properties of biological analytes at the single entity level. The systems developed for these purposes consist of piezoelectrica ...

EPFL2022

Strong temperature-dependent thermoelectric power of IrMn(3)thin films of different thicknesses

Jean-Philippe Ansermet, Haiming Yu, Junfeng Hu, Mukund Krishna Kothari

IrMn(3)thin films were experimentally characterized by thermoelectric power and resistivity as a function of temperature and sample thickness. The Seebeck coefficient shows strong temperature dependence and the value increases with temperature up to 350 K. ...

IOP PUBLISHING LTD2021

Synthesis, structural and magnetic characterization of thin films of the chiral magnets CoZnMn and FeGe

Anna Kúkol'ová

Skyrmions are topologically protected nanometer-sized magnetic vortices that have sparked interest for future spintronics applications aiming at high-density, high-speed and low-power consuming magnetic memory devices. One type of skyrmions appears in non- ...

EPFL2021

Crossover between distinct symmetries in solid solutions of rare earth nickelates

Jean-Marc Triscone, Duncan Thomas Lindsay Alexander, Bernat Mundet

A strong coupling of the lattice to functional properties is observed in many transition metal oxide systems, such as the ABO(3) perovskites. In the quest for tailor-made materials, it is essential to be able to control the structural properties of the com ...

2021

Soft functional fibers for mechanical sensing and actuation

Andreas Leber

The measurement and generation of mechanical deformations is a key functionality in health monitoring, human-machine interaction, and soft robotics. However, current methods typically rely on small and hard transducers, which result in poor performance, cu ...

EPFL2021

Challenges and Applications to Operando and In Situ TEM Imaging and Spectroscopic Capabilities in a Cryogenic Temperature Range

Martial Duchamp, Vasiliki Tileli, Reinis Ignatans

In this Account, we describe the challenges and promising applications of transmission electron microscopy (TEM) imaging and spectroscopy at cryogenic temperatures. Our work focuses on two areas of application: the delay of electron-beam-induced degradatio ...

AMER CHEMICAL SOC2021

How free exciton-exciton annihilation lets bound exciton emission dominate the photoluminescence of 2D-perovskites under high-fluence pulsed excitation at cryogenic temperatures

Michael Graetzel, Jovana Milic, Yang Li, Algirdas Ducinskas

Photoluminescence (PL) spectra of atomically thin 2D lead iodide perovskite films are shown to depend on excited-state density, especially at cryogenic temperatures. At high excited-state densities and low temperatures, free exciton (FE) emission is so sup ...

AMER INST PHYSICS2021