Publications associées à Susceptibilité magnétique des roches

Magnonic crystals with reconfigurable magnetic defects for spin-based microwave electronics

Collective spin excitations can propagate in magnetically ordered materials in the form of waves. These so-called spin waves (SWs) or magnons are promising for low-power beyond-CMOS information processing, which does not rely anymore on the lossy movement ...

EPFL2021

Structural Disorder and Magnetic Order in Atomically Thin Crystals

Michele Pizzochero

This Thesis is mainly devoted to the exploration of the structural disorder and magnetic order in two-dimensional crystals by means of first-principles methodologies. Firstly, we present a comparative study of defect formation in the semiconducting 2H and ...

EPFL2020

Quantum state manipulation of single atom magnets using the hyperfine interaction

Harald Brune, François Patthey, Donat Fabian Natterer, Edgar Fernandes, Patrick Robert Forrester, Dante Philippe Sblendorio

The magnetic quantum states of holmium single atom magnets on MgO(100) have proven extremely robust when exposed to high magnetic fields and temperatures up to 35 K. Here we address the stability of Ho at small magnetic fields, where the hyperfine interact ...

2019

Magnetic Stability of Single Lanthanide Atoms on Graphene

Romana Baltic

This thesis presents a study of the magnetism of surface supported atoms performed principally with XMCD spectroscopy and multiplet calculations. The objective of the research was twofold: first, to study the underlying interactions and conditions governi ...

EPFL2018

High-Temperature Ferrimagnetism with Large Coercivity and Exchange Bias in the Partially Ordered 3d/5d Hexagonal Perovskite Ba2Fe1.12Os0.88O6

Philip Pattison

Double perovskite oxides A(2)BB'O-6 combining 3d and 4d or 5d transition metal ions at the B and B' sites feature a variety of magnetic and magneto-electric properties. Targeting Ba2FeOsO6, we synthesized powder samples of nonstoichiometric Ba2Fe1.12Os0.88 ...

American Chemical Society2017

Magnetic remanence in single atoms

Harald Brune, François Patthey, Stefano Rusponi, Christian Wäckerlin, Jan Gui-Hyon Dreiser, Pietro Gambardella, Fabio Donati, Zeljko Sljivancanin, Aparajita Singha, Romana Baltic, Katharina Johanna Diller, Edgar Fernandes

A permanent magnet retains a substantial fraction of its saturation magnetization in the absence of an external magnetic field. Realizing magnetic remanence in a single atom allows for storing and processing information in the smallest unit of matter. We s ...

American Association for the Advancement of Science2016

Leakage Flux Modelling in Magnetic Fluids Test Bench

Yves Perriard, Yoan René Cyrille Civet, Cécile Gisèle Aimée Jeannine Cuchet, Christophe Espanet

The proposed paper discusses a new methodology to monitor the B-H curve of magnetic fluids, which have low relative permeability. The set-up consists of a magnetic circuit which encloses a sample. A first coil allows creating a magnetic field into the samp ...

IEEE2016

Modeling Ferro- and Antiferromagnetic Interactions in Metal-Organic Coordination Networks

Klaus Kern, Sebastian Stepanow, Tzu-Chun Tseng, Violetta Sessi, Alexander Langner, Nasiba Abdurakhmanova, Christopher Seiji Kley

Magnetization curves of two rectangular metalorganic coordination networks formed by the organic ligand TCNQ (7,7,8,8-tetracyanoquinodimethane) and two different (Mn and Ni) 3d transition metal atoms [M(3d)] show marked differences that are explained using ...

Amer Chemical Soc2015

Temperature and field dependence of magnetic domains in La1.2Sr1.8Mn2O7

Colossal magnetoresistance and field-induced ferromagnetism are well documented in manganite compounds. Since domain wall resistance contributes to magnetoresistance, data on the temperature and magnetic field dependence of the ferromagnetic domain structu ...

Amer Physical Soc2015

Tracking Temperature-Dependent Relaxation Times of Ferritin Nanomagnets with a Wideband Quantum Spectrometer

Klaus Kern, Markus Ternes

We demonstrate the tracking of the spin dynamics of ensemble and individual magnetic ferritin proteins from cryogenic up to room temperature using the nitrogen-vacancy color center in diamond as a magnetic sensor. We employ different detection protocols to ...

Amer Physical Soc2014

Coexistence of localized and collective magnetism in the coupled-spin-tetrahedra system Cu4Te5O12C14

Helmuth Berger

We report high-field magnetization, electron spin resonance (ESR), and Raman scattering measurements of the coupled spin-tetrahedra system Cu4Te5O12C14 with magnetic ordering at T-N = 13.6 K. We find thermodynamic and spectroscopic signatures for the conco ...

Amer Physical Soc2014

Magnetic states and spin-wave modes in single ferromagnetic nanotubes

Daniel Rüffer

In this thesis the electrical properties, magnetic states and spin wave resonances of individual magnetically hollow ferromagnetic nanotubes have been studied. They were prepared from the different materials Nickel (Ni), Permalloy (Py) and Cobalt-Iron-Boro ...

EPFL2014

Growth and Magnetism of Nanostructures Investigated by STM, MOKE, and XMCD

Alberto Cavallin

This thesis presents our studies on nanostructures growth and magnetism, mainly based on scanning tunneling microscopy (STM), magneto-optical Kerr effect (MOKE), and x-ray magnetic circular dichroism (XMCD) measurements. In most of these experiments, nanos ...

EPFL2013

Magnetization States of All-Oxide Spin Valves Controlled by Charge-orbital Ordering of Coupled Ferromagnets

Charge-orbital ordering is commonly present in complex transition metal oxides and offers interesting opportunities for novel electronic devices. In this work, we demonstrate for the first time that the magnetization states of the spin valve can be directl ...

Nature Publishing Group2013

Magnetism of Single Adatoms and Small Adsorbed Clusters Investigated by Means of Low-Temperature STM

Quentin Dubout

This thesis works reports on the magnetic properties of single transition metal atoms and hydrogenated compounds adsorbed on crystal surfaces. It is an experimental study, based on scanning tunneling microscopy (STM), initiated by the project of demonstrat ...

EPFL2013

Pr4Fe2As2Te1-xO4: A layered FeAs-based superconductor

László Forró, Richard Gaal, Janusz Andrzej Karpinski, Andrea Pisoni, Sergiy Katrych

We report crystal growth at high pressure, structure determination, and magnetic and transport studies of an oxypnictide superconductor Pr4Fe2As2Te1-xO4. Its structure resembles the known 1111 phase except for the considerably larger c lattice constant and ...

Amer Physical Soc2013

Two-step transition in a magnetoelectric ferrimagnet Cu2OSeO3

Ivica Zivkovic, Helmuth Berger

We report a detailed single-crystal investigation of a magnetoelectric ferrimagnet Cu2OSeO3 using dc magnetization and ac susceptibility along the three principal directions [100], [110], and [111]. We have observed that in small magnetic fields two magnet ...

2012

High resolution in situ magneto-optic Kerr effect and scanning tunneling microscopy setup with all optical components in UHV

Harald Brune, Stefano Rusponi, Philipp Buluschek, Nicolas Weiss, Anne Lehnert, Matthias Treier

A surface magneto-optic Kerr effect (MOKE) setup fully integrated in an ultrahigh vacuum chamber is presented. The system has been designed to combine in situ MOKE and scanning tunneling microscopy. Magnetic fields up to 0.3 T can be applied at any angle i ...

2009

Magnetism of individual adatoms and of epitaxial monolayers

Anne Lehnert

This thesis reports on the magnetism of low coordinated Fe and Co atoms in different chemical and electronic environments. The objective of this research was to contribute to the fundamental understanding of the magnetic properties, such as magneto-crystal ...

EPFL2009

Near-zero-moment ferromagnetism in the semiconductor SmN

Simon Granville, Harry Joseph Trodahl

The magnetic behavior of SmN has been investigated in stoichiometric polycrystalline films. All samples show ferromagnetic order with Curie temperature (T-C) of 27 3 K, evidenced by the occurrence of hysteresis below T-C. The ferromagnetic state is charact ...

2008