Publications associées à Giant switchable non thermally-activated conduction in 180 degrees domain walls in tetragonal Pb(Zr,Ti)O-3

Hydrogen-induced tunable remanent polarization in a perovskite nickelate

Materials with field-tunable polarization are of broad interest to condensed matter sciences and solid-state device technologies. Here, using hydrogen (H) donor doping, we modify the room temperature metallic phase of a perovskite nickelate NdNiO3 into an ...

Nature Portfolio2024

Instabilities in Elastic and Magneto-Elastic Beams and Shells: from Shell Buckling to the Design of a Programmable Braille Reader

Arefeh Abbasi

In this thesis, we conduct a comprehensive investigation into structural instabilities of both elastic and magneto-elastic beams and shells, resulting in a creative proposal to design a programmable braille reader. Methodologically, we combine numerical si ...

EPFL2024

Snap buckling of bistable beams under combined mechanical and magnetic loading

Pedro Miguel Nunes Pereira de Almeida Reis, Dong Yan, Tomohiko Sano, Arefeh Abbasi

We investigate the mechanics of bistable, hard-magnetic, elastic beams, combining experiments, finite-element modelling (FEM) and a reduced-order theory. The beam is made of a hard magneto-rheological elastomer, comprising two segments with antiparallel ma ...

ROYAL SOC2023

Spin Textures in 2D Magnets

Lukas Powalla

The continuous reduction of the structural size in nanotechnology slowed down over the last decade, approaching the natural limit of single atoms as building blocks of matter. Therefore, intensive research is directed toward exploring new frontiers, in par ...

EPFL2023

Energy-Efficient Electronic Functions Based on the Co-integration of 2D and Ferroelectric Materials

Sadegh Kamaei Bahmaei

The digital revolution has significantly transformed our world over the past decades, driven by the scaling of transistor dimensions and the exponential increase in computation power. However, as the CMOS scaling era approaches its end, the semiconductor i ...

EPFL2023

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

Domain Imaging and Switching Dynamics in BaTiO3-Based Photonic Integrated Devices

Jacqueline Geler Kremer

Keeping up with our constantly connected lifestyle of instant messages and video streaming has its repercussions. Data centers have been gobbling up resources becoming a significant share of the energy used worldwide. To keep up with demand and curb the en ...

EPFL2023

Direct observation of exchange anisotropy in the helimagnetic insulator Cu2OSeO3

Arnaud Magrez, Jonathan White, Chen Luo, Priya Ranjan Baral

The helical magnetic structures of cubic chiral systems are well explained by the competition among Heisen-berg exchange, Dzyaloshinskii-Moriya interaction, cubic anisotropy, and anisotropic exchange interaction (AEI). Recently, the role of the latter has ...

AMER PHYSICAL SOC2023

Semiconductor-based device architectures in multimaterial fibers

William Nicolas Duncan Esposito

Semiconductor materials have given rise to today's digital technology and consumer electronics. Widespread adoption is closely linked to the ability to process and integrate them in devices at scale. Where flexibility and large surfaces are required, such ...

EPFL2023

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

Magnetic structure of the topological semimetal Co3Sn2S2

Henrik Moodysson Rønnow, Ivica Zivkovic, Jian Rui Soh

Co3Sn2S2 has recently been predicted to be a Weyl semimetal in which magnetic order is key to its behavior as a topological material. Here, we report unpolarized neutron diffraction and spherical neutron polarimetry measurements, supported by magnetization ...

AMER PHYSICAL SOC2022

Defect-induced magnetism in homoepitaxial SrTiO3

Mihai Adrian Ionescu, Daesung Park

Along with recent advancements in thin-film technologies, the engineering of complex transition metal oxide heterostructures offers the possibility of creating novel and tunable multifunctionalities. A representative complex oxide is the perovskite stronti ...

AIP Publishing2022

Canted antiferromagnetic phases in the candidate layered Weyl material EuMnSb2

Xiaoqiang Wang, Xiao Wang

EuMnSb2 is a candidate topological material which can be tuned towards a Weyl semimetal, but there are differing reports for its antiferromagnetic (AFM) phases. The coupling of bands dominated by pure Sb layers hosting topological fermions to Mn and Eu mag ...

AMER PHYSICAL SOC2022

Exploring negative capacitance and neuromorphic devices based on CMOS-compatible ferroelectric HfO2

Carlotta Gastaldi

Ferroelectric materials are explored for numerous applications thanks to their properties associated with electrically switchable spontaneous polarization. Perovskites are an established class of ferroelectrics used for sensors and actuators. However, they ...

EPFL2022

Increasing Magnetic Anisotropy in Bimetallic Nanoislands Grown on fcc(111) Metal Surfaces

Harald Brune, Stefano Rusponi, Sergio Vlaic, Dimitrios Mousadakos

The magnetic properties and the atomic scale morphology of bimetallic two-dimensional nanoislands, epitaxially grown on fcc(111) metal surfaces, have been studied by means of Magneto-Optical Kerr Effect and Scanning Tunneling Microscopy. We investigate the ...

MDPI2022

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

Field-dependent roughness of moving domain walls in a Pt/Co/Pt magnetic thin film

Elisabeth Agoritsas

The creep motion of domain walls driven by external fields in magnetic thin films is described by universal features related to the underlying depinning transition. One key parameter in this description is the roughness exponent characterizing the growth o ...

2021

Intrinsic switching in Si-doped HfO2: A study of Curie-Weiss law and its implications for negative capacitance field-effect transistor

Igor Stolichnov, Mihai Adrian Ionescu, Teodor Rosca, Ali Saeidi, Matteo Cavalieri, Eamon Patrick O'Connor, Carlotta Gastaldi, Sadegh Kamaei Bahmaei

HfO2-based ferroelectrics are considered a promising class of materials for logic and memory applications due to their CMOS compatibility and ferroelectric figures of merit. A steep-slope field-effect-transistor (FET) switch is a device for logic applicati ...

AMER INST PHYSICS2021

Gate energy efficiency and negative capacitance in ferroelectric 2D/2D TFET from cryogenic to high temperatures

Mihai Adrian Ionescu, Teodor Rosca, Ali Saeidi, Matteo Cavalieri, Luca Capua, Carlotta Gastaldi, Sadegh Kamaei Bahmaei

We report the fabrication process and performance characterization of a fully integrated ferroelectric gate stack in a WSe2/SnSe2 Tunnel FETs (TFETs). The energy behavior of the gate stack during charging and discharging, together with the energy loss of a ...

NATURE PORTFOLIO2021

Sequential manufacturing via intra-additive hybrid materials approach for fully roll-to-roll processed flexible organic thin film transistors

Jaemin Kim

Conventional conductive films that are used as electrodes in organic thin film transistors (OTFTs) are susceptible to mechanical deformation, limiting the applicability of such films in flexible wearable electronic devices. To address this limitation, a hy ...

ELSEVIER SCI LTD2021