A5038231296- Magnetic properties of thin films
- Advanced Chemical Physics Studies
- Electron and X-Ray Spectroscopy Techniques
- Advanced Electron Microscopy Techniques and Applications
- Topological Materials and Phenomena
- Physics of Superconductivity and Magnetism
- Photocathodes and Microchannel Plates
- X-ray Spectroscopy and Fluorescence Analysis
- Electronic and Structural Properties of Oxides
- Laser-Matter Interactions and Applications
- Advanced X-ray Imaging Techniques
- Semiconductor materials and devices
- Surface and Thin Film Phenomena
- Advanced Condensed Matter Physics
- Quantum and electron transport phenomena
- Ga2O3 and related materials
- Superconducting Materials and Applications
- Transition Metal Oxide Nanomaterials
- GaN-based semiconductor devices and materials
- Graphene research and applications
- Particle Accelerators and Free-Electron Lasers
- Electrochemical Analysis and Applications
- TiO2 Photocatalysis and Solar Cells
- Iron-based superconductors research
- Magneto-Optical Properties and Applications
AREA Science Park
2007-2023
Istituto Officina dei Materiali
2011-2021
University of Cologne
2020
Elettra-Sincrotrone Trieste S.C.p.A.
2020
Center for Free-Electron Laser Science
2018
Universität Hamburg
2018
University of California, San Diego
2018
Synchrotron soleil
2010-2018
European Theoretical Spectroscopy Facility
2018
Spin-based electronics in topological insulators (TIs) is favored by the long spin coherence(1,2) and consequently fault-tolerant information storage. Magnetically doped TIs are ferromagnetic up to 13 K,(3) well below any practical operating condition. Here we demonstrate that long-range ferromagnetism at ambient temperature can be induced Bi(2-x)Mn(x)Te(3) magnetic proximity effect through deposited Fe overlayer. This result opens a new path interface-controlled TI-based spintronic devices.
We report the main characteristics of advanced photoelectric effect experiments beamline, operational at Elettra storage ring, featuring a fully independent double branch scheme obtained by use chicane undulators and able to keep polarization control in both linear circular mode. The paper describes novel technical solutions adopted, namely, (a) design quasiperiodic undulator resulting optimized suppression higher harmonics over large photon energy range (10-100 eV), (b) thermal stability...
A new insertion device beamline is now operational on straight section 8 at the SOLEIL synchrotron radiation source in France. The and experimental station were developed to optimize study of dynamics electronic magnetic properties materials. Here we present main technical characteristics installation general principles behind them. composed two APPLE II type devices. monochromator with plane gratings spherical mirrors working energy range 40–1500 eV. It equipped VLS, VGD allow user...
Synchrotron radiation time structure is becoming a common tool for studying dynamic properties of materials. The main limitation often the wide domain user would like to access with pump-probe experiments. In order perform photoelectron spectroscopy experiments over scales from milliseconds picoseconds it mandatory measure at which each measured was created. For this reason usual CCD camera-based two-dimensional detection electron energy analyzers has been replaced by new delay-line detector...
Complete photoemission experiments, enabling measurement of the full quantum set photoelectron final state, are in high demand for studying materials and nanostructures whose properties determined by strong electron spin correlations. Here implementation new polarimeter VESPA (Very Efficient Spin Polarization Analysis) at APE-NFFA beamline Elettra is reported, which based on exchange coupling between a ferromagnetic surface reflectometry setup. The system was designed to be integrated with...
We present a new experimental setup for performing X-ray Absorption Spectroscopy (XAS) in the soft range at ambient pressure. The pressure XAS is fully compatible with ultra high vacuum environment of synchrotron radiation spectroscopy beamline end station by means ultrathin Si3N4 membranes acting as windows beam and seal atmospheric sample environment. detection performed total electron yield (TEY) mode probing drain current from picoammeter. signal/noise ratio achievable TEY mode, combined...
Here, we report on a novel narrowband High Harmonic Generation (HHG) light source designed for ultrafast photoelectron spectroscopy (PES) solids. Notably, at 16.9 eV photon energy, the harmonics bandwidth equals 19 meV. This result has been obtained by seeding HHG process with 230 fs pulses 515 nm. The ultimate energy resolution achieved polycrystalline Au sample 40 K is ∼22 meV eV. These parameters set new benchmark sources and have varying repetition rate up to 200 kHz and, consequently,...
In this work, we apply for the first time ambient pressure operando soft X-ray absorption spectroscopy (XAS) to investigate location, structural properties, and reactivity of defective sites present in prototypical metal-organic framework HKUST-1. We obtained direct evidence that Cu+ form upon temperature treatment powdered HKUST-1 at 160 °C they are largely distributed on material surface. Further, a thorough characterization Cu+/Cu2+ dimeric complexes arising from temperature-induced...
The influence of magnetic dopants on the electronic and chemical environments in topological insulators (TIs) is a key factor when considering possible spintronic applications based surface state properties. Here we provide spectroscopic evidence for presence distinct behavior bulk doping Bi2Te3. inclusion Mn Bi2Te3 induces genuine dilute ferromagnetic state, with reduction band gap as content increased. Deposition Fe surface, other hand, favors formation iron telluride already at coverages...
We report the study of anatase TiO2(001)-oriented thin films grown by pulsed laser deposition on LaAlO3(001). A combination in situ and ex methods has been used to address both origin Ti3+-localized states their relationship with structural electronic properties surface subsurface. Localized in-gap are analyzed using resonant X-ray photoelectron spectroscopy related Ti3+ configuration, homogeneously distributed over entire film thickness. find that an increase oxygen pressure corresponds...
We use time-resolved X-ray photoelectron spectroscopy to probe the electronic and magnetization dynamics in FeRh films after ultrafast laser excitations. present experimental theoretical results which investigate structure of during first-order phase transition, identifying a clear signature magnetic phase. find that spin polarized feature at Fermi edge is fingerprint status system independent long-range ferromagnetic alignment domains. this follow transition induced by pulse pump-probe...
The SOLEIL synchrotron radiation source is regularly operated in special filling modes dedicated to pump–probe experiments. Among others, the low-α mode operation characterized by shorter pulse duration and represents natural bridge between 50 ps pulses femtosecond Here, capabilities of experimental set-ups developed at TEMPO beamline perform experiments with soft X-rays based on photoelectron or photon detection are presented. A 282 kHz repetition-rate laser synchronized time structure...
In the light of hybrid functional density-functional theory calculations core-excited and core-ionized states, this paper discusses original N $1s$ x-ray photoemission spectroscopy (XPS) near-edge absorption fine-structure (NEXAFS) experimental data on single-domain (vicinal) Si(001)-$2\ifmmode\times\else\texttimes\fi{}1$ surface saturated by ${\text{NH}}_{3}$ at 300 K. The theoretical approach enables to discuss vibrational shape XPS spectrum quantifies binding-energy splitting due intrarow...
The discontinuity in the lattice periodic potential at surfaces often leads to creation of new electronic surface states. We developed a photoemission based Fermi tomography whose sensitivity allowed us quantify charge redistribution on Be(0001) surface. volume enclosed by bulklike is significantly reduced surface, consistent with transfer two states as estimated from area within their two-dimensional contours. This result represents first quantification natural termination.
ULTRASPIN is an apparatus devoted to the measurement of spin polarization (SP) electrons ejected from solid surfaces in a UHV environment. It designed exploit ultrafast light sources (free electron laser or high harmonic generation) and perform (photo)electron analysis by arrangement Mott scattering polarimeters that measure full SP vector. The system consists two interconnected vessels: one for surface science sample cleaning treatments, e-beam deposition ultrathin films, low energy...
We report on orbital-dependent quasiparticle dynamics in EuFe$_2$As$_2$, a parent compound of Fe-based superconductors and novel way to experimentally identify this behavior, using time- angle-resolved photoelectron spectroscopy across the spin density wave transition. observe two different relaxation time scales for photo-excited d$_x$$_z$/d$_y$$_z$ d$_x$$_y$ electrons. While electrons relax faster through electron-electron scattering channel, showing an itinerant character, form...
The manipulation of ferromagnetic layer magnetization via electrical pulse is driving an intense research due to the important applications that this result will have on memory devices and sensors. In study we realized a magnetotunnel junction in which one made Galfenol (Fe1-xGax) possesses highest magnetostrictive coefficient known. multilayer stack has been grown by molecular beam epitaxy e-beam evaporation. Optical lithography physical etching combined obtain 20x20 micron sized pillars....
Here we report on a novel High Harmonic Generation (HHG) light source designed for space charge free ultrafast photoelectron spectroscopy (PES) solids. The ultimate overall energy resolution achieved polycrystalline Au sample is ~22 meV at 40 K. These results have been obtained photon of 16.9 eV with pulse bandwidth ~19 meV, by varying, up to 200 kHz, the pulses repetition rate and fluence sample. features set new benchmark tunable narrowband HHG sources. By comparing PES duration ~105 fs,...