Publications de Arnaud Magrez | EPFL Graph Search

Fluctuation-driven topological Hall effect in room-temperature itinerant helimagnet Fe3Ga4

Arnaud Magrez, Ivica Zivkovic, Priya Ranjan Baral, Youngro Lee

The topological Hall effect (THE) is a hallmark of a non-trivial geometric spin arrangement in a magnetic metal, originating from a finite scalar spin chirality (SSC). The associated Berry phase is often a consequence of non-coplanar magnetic structures id ...

2025

Short-wave magnons with multipole spin precession detected in the topological bands of a skyrmion lattice

Arnaud Magrez, Henrik Moodysson Rønnow, Dirk Grundler, Ping Che, Thomas Schönenberger, Priya Ranjan Baral

Topological magnon bands enable uni-directional edge transport without backscattering, enhancing the robustness of magnonic circuits and providing a novel platform for exploring quantum transport phenomena. Magnetic skyrmion lattices, in particular, host a ...

Springer Science and Business Media LLC2025

Advances in Crystal Growth: Pioneering Materials for Tomorrow’s Technologies

Arnaud Magrez, Yong Liu

2025

Imaging magnetic spiral phases, skyrmion clusters, and skyrmion displacements at the surface of bulk Cu2OSeO3

Arnaud Magrez

Surfaces – by breaking bulk symmetries, introducing roughness, or hosting defects – can significantly influence magnetic order in magnetic materials. Determining their effect on the complex nanometer-scale phases present in certain non-centrosymmetric magn ...

2024

Dynamics of K2Ni2(SO4)3 governed by proximity to a 3D spin liquid model

Arnaud Magrez, Henrik Moodysson Rønnow, Ivica Zivkovic, Virgile Yves Favre, Jian Rui Soh

Quantum spin liquids (QSLs) have become a key area of research in magnetism due to their remarkable properties, such as long-range entanglement, fractional excitations, and topologically protected phenomena. Recently, the search for QSLs has expanded into ...

Nature Research2024

Growth and Characterization of High-Quality YTiO3 Single Crystals: Minimizing Ti4+ Containing Impurities and TiN Formation

Arnaud Magrez, Yong Liu

We report the growth of YTiO3 single crystals using different starting materials with the nominal compositions, (1) stoichiometric YTiO3; (2) oxygen deficient YTiO2.925; (3) oxygen deficient YTiO2.85, and different atmospheres, (1) 97%Ar/3%H2; (2) Ar; (3) ...

2024

On the synergistic interplay between annealing temperature and time and additive concentration for efficient and stable FAPbI3 perovskite solar cells

Andreas Schueler, Arnaud Magrez

Formamidinium-based lead triiodide perovskite (FAPI) is the workhorse candidate for highly efficient perovskite solar cells owing to its ideal bandgap and phase purity. An essential condition to that is the formation of a pure alpha-black phase, commonly t ...

ELSEVIER2024

High-Temperature Phase Transitions Preceding the Decomposition of Mixed Valence Aluminum Titanate Pseudobrookite

Arnaud Magrez, Henrik Moodysson Rønnow, Ivica Zivkovic, Davor Tolj, Yong Liu

Dark blue single crystals of Al1.753+Ti1.04+Ti0.253+O5 were grown with a novel synthesis method based on the reaction of a Ti3+/Ti4+-containing langbeinite melt and porous alpha-alumina crucible. The obtained needles crystallize in the pseudobrookite struc ...

Amer Chemical Soc2024

Electron Glass Phase with Resilient Zhang-Rice Singlets in LiCu3O3

László Forró, Rosario Scopelliti, Arnaud Magrez, Krunoslav Prsa, Henrik Moodysson Rønnow, Simon Karl Moser, Jens Christian Johannsen, Paul Gregory Freeman, Edoardo Martino, Gianmarco Gatti

LiCu3O3 is an antiferromagnetic mixed valence cuprate where trilayers of edge -sharing Cu(II)O (3d9) are sandwiched in between planes of Cu(I) (3d10) ions, with Li stochastically substituting Cu(II). Angle resolved photoemission spectroscopy (ARPES) and de ...

Amer Physical Soc2024

High-resolution crystal structure of the double nitrate hydrate [La(NO3)6]2[Ni(H2O)6]3·6H2O

Arnaud Magrez, Yong Liu

This study introduces bis[hexakis(nitrato-κ2 O,O′)lanthanum(III)] tris[hexaaquanickel(II)] hexahydrate, [La(NO3)6]2[Ni(H2O)6]3·6H2O, with a structure refined in the hexagonal space group R . The salt comprises [La(NO3)6]3- icosahedra and [Ni(H2O) ...

2024

Real-and reciprocal space characterization of the three-dimensional charge density wave in quasi-one-dimensional CuTe

Arnaud Magrez, Jan Hugo Dil, Michele Puppin, Fei Guo

Low-dimensional materials are susceptible to electronic instabilities such as charge density waves (CDWs), originating from a divergence in the Lindhard electron response function, combined with a finite electron-phonon coupling strength. In this paper, we ...

American Physical Society (APS)2024

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

Light-Induced Metastable Hidden Skyrmion Phase in the Mott Insulator Cu2OSeO3

Thomas La Grange, Arnaud Magrez, Henrik Moodysson Rønnow, Fabrizio Carbone, Ivan Madan, Benoît Guilhem Michel Binh Truc, Simone Gargiulo, Phoebe Marie Tengdin

The discovery of a novel long-lived metastable skyrmion phase in the multiferroic insulator Cu2OSeO3 visualized with Lorentz transmission electron microscopy for magnetic fields below the equilibrium skyrmion pocket is reported. This phase can be accessed ...

Wiley-V C H Verlag Gmbh2023

Synthesis and crystal structure of Fe[SeO4]OH and prediction of polytypes in the extended R[MO4]Z family

Arnaud Magrez, Alla Arakcheeva, Benoît Guilhem Michel Binh Truc

Single crystals of Fe[SeO4]OH have been synthesized by hydrothermal treatment. The Fe[SeO4]OH structure was investigated using the superspace approach. It is shown that the structure belongs to a family of compounds including kieserite-like and pauflerite- ...

ROYAL SOC CHEMISTRY2023

Imaging the Ultrafast Coherent Control of a Skyrmion Crystal

Arnaud Magrez, Henrik Moodysson Rønnow, Fabrizio Carbone, Dirk Grundler, Ivan Madan, Ping Che, Thomas Schönenberger, Priya Ranjan Baral, Alexey Sapozhnik, Simone Gargiulo

Exotic magnetic textures emerging from the subtle interplay between thermodynamic and topological fluctuation have attracted intense interest due to their potential applications in spintronic devices. Recent advances in electron microscopy enable the imagi ...

American Physical Society2022

Tuning Topological Spin Textures in Size-Tailored Chiral Magnet Insulator Particles

Thomas La Grange, Arnaud Magrez, Henrik Moodysson Rønnow, Ivica Zivkovic, Priya Ranjan Baral

Topological spin textures such as skyrmions hold high potential for use as magnetically active elements in diverse near-future applications. While skyrmions in metallic multilayers attract great attention in this context, unleashing the myriad potential of ...

2022

Direct Visualisation of Skyrmion Lattice Defect Alignment at Grain Boundaries

Arnaud Magrez, Henrik Moodysson Rønnow, Fabrizio Carbone, Thomas Schönenberger

We present a method to directly visualise a statistical analysis of skyrmion defect alignment at grain boundaries in the skyrmion host Cu2OSeO3. Using Lorentz transmission electron microscopy, we collected large data sets with several hundreds of frames co ...

2022

Electric field writing and erasing of skyrmions in magnetoelectric Cu2OSeO3 with an ultralow energy barrier

Marco Cantoni, Arnaud Magrez, Henrik Moodysson Rønnow, Fabrizio Carbone

Skyrmions are chiral magnetic textures with non-trivial topology, and due to their unique properties they are widely considered as promising information carriers in novel magnetic storage applications. While electric field writing/erasing and manipulation ...

ROYAL SOC CHEMISTRY2022

Self-flux-grown Ba4Fe4ClO9.5-x crystals exhibiting structures with tunable modulation

Arnaud Magrez, Alla Arakcheeva, Priya Ranjan Baral

The synthesis and X-ray structural study of the new family of compounds Ba4Fe4ClO9.5-x with tunable structural modulation are reported. The framework of the structure has the Ba2Fe4O9.5-x composition, with open hexagonal channels extending along the c-axis ...

2022

Hidden bulk and surface effects in the spin polarization of the nodal-line semimetal ZrSiTe

Helmuth Berger, Marco Grioni, Arnaud Magrez, Oleg Yazyev, Alberto Crepaldi, Mauro Fanciulli, Gianmarco Gatti, Daniel Gosalbez Martinez, Silvan Dino Marcos Roth

Local inversion symmetry breaking in centrosymmetric materials can lead to large spin polarization of the electronic band structure in separate sectors of the unit cell. Here, the authors reveal such hidden spin polarisation in ZrSiTe using spin and angle ...

NATURE RESEARCH2021