LMX: Laboratory for Multiscale materials eXperiments
The Laboratory for Multiscale materials eXperiments (LMX) focusses on designing novel functional materials in poly- and single crystalline form, as thin films and as multilayers. Read more about LMX
The Young Scientist Award 2020 goes to Claire Donnelly for advances in the experimental characterization of spin textures and their dynamics in three dimensions with X-ray techniques.
Claire Donnelly, a former Ph.D and postdoc at PSI in the Mesoscopic Systems Group, is currently a Leverhulme Early Career Research Fellow in the Cavendish Laboratory, University of Cambridge. She received her PhD in 2017 from the ETH Zurich for her work on hard X-ray tomography of three-dimensional magnetic structures based at the Paul Scherrer Institute. Following a postdoc at the ETH Zurich, she moved to the University of Cambridge and the Cavendish in January 2019, where she is focusing on the dynamics of three-dimensional magnetic nanostructures.
Her research focuses on three dimensional magnetic systems, which she studies using sophisticated synchorotron X-rays to determine the three-dimensional magnetic configurations, and their dynamic behaviour, at the nanoscale.
TecDay is an SATW initiative that was developed at the Kantonsschule Limmattal in 2007 and has since been rolled out to more than 60 secondary schools across Switzerland. By the end of 2017 it had reached around 45,000 students and 5,000 teachers. In December 2019 the LMX contributed in one module, that received a total of 16 students over the course of a morning. The module was organized in three different “stations”, each one focusing on one topic or area that the group is working on.
Proximity-Induced Novel Ferromagnetism Accompanied with Resolute Metallicity in NdNiO3 Heterostructure
Employing X-ray magnetic circular dichroism (XMCD), angle-resolved photoemission spectroscopy (ARPES), and momentum-resolved density fluctuation (MRDF) theory, the magnetic and electronic properties of ultrathin NdNiO3 (NNO) film in proximity to ferromagnetic (FM) La0.67Sr0.33MnO3 (LSMO) layer are investigated. The experimental data shows the direct magnetic coupling between the nickelate film and the manganite layer which causes an unusual ferromagnetic (FM) phase in NNO. Moreover, it is shown the metal–insulator transition in the NNO layer, identified by an abrupt suppression of ARPES spectral weight near the Fermi level (EF), is absent. This observation suggests that the insulating AFM ground state is quenched in proximity to the FM layer. Combining the experimental data (XMCD and AREPS) with the momentum-resolved density fluctuation calculation (MRDF) reveals a direct link between the MIT and the magnetic orders in NNO systems. This work demonstrates that the proximity layer order can be broadly used to modify physical properties and enrich the phase diagram of RENiO3 (RE = rare-earth element).
The crystal structure and magnetic correlations in triangular antiferromagnet FeGa2S4 are studied by x-ray diffraction, magnetic susceptibility, neutron diffraction, and neutron inelastic scattering. We report significant mixing at the cation sites and disentangle magnetic properties dominated by major and minor magnetic sites.
RENiO3 Single Crystals (RE = Nd, Sm, Gd, Dy, Y, Ho, Er, Lu) Grown from Molten Salts under 2000 bar of Oxygen Gas Pressure
Schematic representation of the method used to grow RENiO3 nickelate single crystals covering the full 4f series and Y. This novel procedure, based on the use of moderate oxygen gas pressures (2000 bar), solvothermal growth in a temperature gradient, and highly reactive eutectic salt mixtures as fluxes, yields prismatic-shaped crystals with flat facets and sizes up to ∼75 μm.
At the liquid–gas phase transition in water, the density has a discontinuity at atmospheric pressure; however, the line of these first-order transitions defined by increasing the applied pressure terminates at the critical point, a concept ubiquitous in statistical thermodynamics. In correlated quantum materials, it was predicted and then confirmed experimentally that a critical point terminates the line of Mott metal–insulator transitions, which are also first-order with a discontinuous charge carrier density. In quantum spin systems, continuous quantum phase transitions have been controlled by pressure, applied magnetic field and disorder, but discontinuous quantum phase transitions have received less attention.
Unconventional Transverse Transport above and below the Magnetic Transition Temperature in Weyl Semimetal EuCd2As2
As exemplified by the growing interest in the quantum anomalous Hall effect, the research on topology as an organizing principle of quantum matter is greatly enriched from the interplay with magnetism. In this vein, we present a combined electrical and thermoelectrical transport study on the magnetic Weyl semimetal EuCd2As2. Unconventional contribution to the anomalous Hall and anomalous Nernst effects were observed both above and below the magnetic transition temperature of EuCd2As2, indicating the existence of significant Berry curvature.