News & Scientific Highlights

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Elusive multiferroicity in RNiO3 perovskites

In our recent paper we examined YNiO3 and proved that the RNiO3 type material known for its metal-insulator transition is in fact a type II multiferroic. We provide direct evidence of an electric-field-driven switch of the noncolliear magnetic state finally confirming the proposed type II multiferroic nature of YNiO3.

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Mechanism For All-Optical Magnetization Switching

X-rays reveal a non-collinear magnetic state as the base for all-optical magnetization switching.

Unusual ferrimagnetism

Unusual ferrimagnetism in CaFe2O4

Rare ferrimagnet states in a phase competing antiferromagnet.

Layered crystal structure

Exchange scaling of ultrafast angular momentum transfer in 4f antiferromagnets

A novel approach to controlling the speed of magnetic processes has been found through resonant magnetic scattering in an antiferromagnetic Lanthanide intermetallics.

Single femtosecond laser pulse excitation of individual cobalt  nanoparticles

Single femtosecond laser pulse excitation of individual cobalt nanoparticles

The interaction of light and magnetism at the nanoscale is a topic of fundamental interest and with potential impact to future spintronics applications. in this work we address theoretically and experimentally the effect of femtosecond laser pulse excitation on the magnetic, structural, and chemical stability of individual magnetic cobalt nanoparticles including the role of the substrate or matrix. Eventually, we discuss possible pathways to achieve laser-induced magnetic switching in individual nanostructures.

This work has been highlighted as "Editors' Suggestion" in Physical Review B.

Remote Operation of the PEEM Endstation

We have recently upgraded the PEEM endstation at the SIM beamline to enable remotely controlled experiments via internet and mailed-in samples. Sample positioning and tilt control is now possible by means of a motorized sample stage. A newly developed computer controlled switchbox is available for remote temperature control and in situ application of electric or magnetic fields to the sample.

Novel Optics

Novel optics enable better X-ray Free Electron Laser experiments

Our research on multifocus off-axis zone plates was accepted in “Optica”, the highest impact journal of the Optical Society of America. In the paper we report on different ways to combine focusing and beam-splitting functionalities in one single optical element.

Microwave excitation leads to a magnetic cascade

Magnon Modes of Microstates and Microwave-Induced Avalanche in Kagome Artificial Spin Ice with Topological Defects

In this work the spin dynamics of microstates in artificial spin ice (ASI) in Ni81Fe19 nanomagnets arranged in an interconnected kagome lattice has been investigated using microfocus Brillouin light scattering, broadband ferromagnetic resonance, magnetic force microscopy, x-ray photoemission electron microscopy, and micromagnetic simulations. The findings are key for the creation of avalanches inside the kagome ASI and reprogrammable magnonics based on ASIs.

Carlos Vaz Selected by the Journal of Materials Chemistry C as Outstanding Reviewer in 2018

SIM beamline scientist Carlos Vaz was recognized as outstanding referee for providing high quality peer review for the Journal of Materials Chemistry C (Royal Society of Chemistry).

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HERCULES school 2019 at SLS

In the week of April 1-5 PSI welcomes 20 PhD students and postdocs taking part in the European HERCULES 2019 school on Neutron and Synchrotron Radiation. They will attend lectures and perform two days of practical courses at several beam lines of the Swiss Light Source.

Cryo-TEM investigation of a free-standing monolayer of a calixarene derivative. The TEM-Picture on the left shows the monolayer deposited on a lacey carbon support. The electron diffraction pattern on the left confirms the formation of a crystalline monolayer

Supramolecular architectures of molecularly thin yet robust free-standing layers

In a collaboration within the network of the Swiss Nanoscience Institute, the formation of free-standing molecular monolayers using self-assembly processes has been demonstrated. The results of the study have been published in the February 2019 issue of Science Advances.

(a) Scanning transmission x-ray microscopy images of magnetic skyrmions stabilized in a nanostructured Pt/Co/Ir disc; (b) Skyrmion-dependent contribution to the Hall resistivity

Discrete Hall contribution of magnetic skyrmions

The reliable electrical detection of magnetic skyrmions is of fundamental importance for the application of such topological magnetic quasi-particles for data storage devices. Researchers in a joint collaboration between the University of Leeds and the PolLux endstation have investigated the electrical detection of isolated magnetic skyrmions in applications-relevant nanostructured devices, observing the presence of a strong skyrmion-dependent contribution to the Hall resistivity.

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HERCULES at the Swiss Light Source

In the week of March 18-23 PSI welcomes 20 PhD students and postdocs taking part in the HERCULES 2018 school on Neutron and Synchrotron Radiation. They will attend lectures and perform two days of practical courses at several beam lines of the Swiss Light Source.

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Carlos Vaz Honored by the American Physical Society as Outstanding Referee 2017

SIM beamline scientist Carlos Vaz was recognized as outstanding referee for providing high quality peer review for the journals of the American Physical Society (APS).

Nanocrystals formed on graphite.

In-situ Studies of the Reactivity of Model Catalysts: Surface Chemistry from flat surfaces to nanoparticles

On 7th February Dr. Christian Papp from University Erlangen (Germany) is visiting the SIM beamline and will give a Photon Science Seminar talk with the title: "In-situ Studies of the Reactivity of Model Catalysts: Surface Chemistry from flat surfaces to nanoparticles"

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Annual Retreat of the Microscopy & Magnetism Group

The Magnetism and Microscopy group has met for its annual retreat meeting in Lungern 11- 15.1.2017 (in the central mountain region of Switzerland) for extensive discussions on its science program. As for other years, after some general introductory lecture into the techniques used, current and future projects have been presented by the PhD students, postdocs, and scientists as well as from guests who collaborate with the group. Discussion went into the time where dinner has been prepared together, followed by some leisure activities on Saturday.

Left: Structure of BaFe2As2 with the motion pattern of the A1g phonon mode (red arrows). 
Right: Pump-induced change of diffraction intensity of the (1 0 5) reflection

Ultrafast structural dynamics of the Fe-pnictide parent compound BaFe2As2

Understanding the interplay of the various degrees of freedom such as the electrons, spins and lattice is essential for many complex materials, including the high-temperature superconductors.

Magnetization dynamics inside a 5 µm x 5 µm structure.(a) Time-resolved PEEM images using XMCD as a magnetic contrast mechanism recorded at a given time delay t after the laser pulse and (b) extracted XMCD contrast as a function of the time delay t for three different ROI, defined in the inset image by the coloured area superimposed on the non-dichroic X-ray absorption of the structure. The 0° incoming laser direction with respect to the structure edge is indicated in the inset by the laser in-plane wave v…

Nanoscale sub-100 picosecond all-optical magnetization switching in GdFeCo microstructure

Ultrafast magnetization reversal driven by femtosecond laser pulses has been shown to be a promising way to write information. Seeking to improve the recording density has raised intriguing fundamental questions about the feasibility of combining ultrafast temporal resolution with sub-wavelength spatial resolution for magnetic recording. Here we report on the experimental demonstration of nanoscale sub-100 ps all-optical magnetization switching, providing a path to sub-wavelength magnetic recording.