Facilities
Large-scale facilities

BACH

General informations

Location
Trieste, Elettra Synchrotron light source
Main techniques and methods
Synchrotron radiation photoemission spectroscopy (SR-PES), High-resolution x-ray photoemission spectroscopy (HR-XPS), Angle resolved photoemission spectroscopy (ARPES), Resonant (angle resolved) photoemission spectroscopy (ResPES), Fast and Temperature-programmed XPS (TP-XPS), Soft x-ray absorption spectroscopy (XAS), XAS in total and partial electron yield mode (TEY and PEY), XAS in total fluorescence yield mode (TFY), X-ray linear and magnetic dichroism (XLD, XMCD), Time-resolved (sub-ns) XAS (TR-XAS), In-situ and in-operando XAS at solid/liquid interfaces
Key instumentation
- BACH beamline
- UHV preparation chamber connected to the measurement chamber
- 4 degree of freedom manipulator with open cycle LN2 and LHe cooling and annealing
- Transferable large area sample holders
- Hemispherical electron energy analyzer (Scienta R3000)
- Set-up for pump-probe time resolved soft x-ray absorption spectroscopy
- Set-up for in-operando soft x-ray absorption spectroscopy (under commissioning)

The beamline offers high-intensity EUV-soft x-rays in a wide energy range (44 eV-1650 eV) with tunable light polarization for multi-technique investigation of the electronic, chemical, structural, magnetic and dynamical properties of materials.

The beamline consists of three branch lines, each one equipped with a specific purpose end-station. The installation of temporary user experimental chambers is available.
(for more details see https://www.elettra.eu/elettra-beamlines/bach.html)

Development of new methods, instrumentation, software

  • An electrochemical flow cell that allows to carry out cyclic voltammetry in situ, electrochemical deposition on a working electrode and to study chemical reactions under in-operando conditions, developed in collaboration with the CNR-IOM technical services, is under commissioning on branch C of the beamline.
  • The renovation of the pump and probe time-resolved XAS set-up has been recently undertaken. The pulsed femtosecond laser (Ti:sapphire laser Coherent Mira HP, 2W, 83.3 MHz, 800 nm) located in a hutch nearby the beamline is now connected through two separate optical paths to the end-stations of branch A and B of the beamline. A safety control system, based on SIRIUS 3RK3 Modular Safety System has been developed by the CNR-IOM technical services for fully safe handling of the laser beam. The pulsed femtosecond laser synchronized with multi-bunch mode synchrotron radiation and fast MCP detector can be used for Pump-Probe measurements of the dynamical evolution of laser-excited states in the time scales of ns and sub-ns.  

Software:

  • LabVIEW platform is used to control the beamline instruments (undulators, beamline pneumatic valves, motors, power supplies, ion gauges…) and for the XAS acquisition. The software interface has been developed by the beamline staff with the support of Elettra.
  • Wavemetrics Igor Pro procedures have been developed by the beamline staff for XAS, XMCD, XPS and ResPES data plotting and pre-processing.

 

Research Activity

The spectroscopic methods available at the BACH beamline have been applied in several fields of modern condensed matter physics, for example on thin molecular and self-assembled overlayers on metal and thin oxide surfaces, single-layer, layered materials and 2D heterostructures, oxide thin films and interfaces, electron correlated materials, superconductors, and novel magnetic materials. The investigations are mostly focused on understanding the interplay between electronic, structural, magnetic, and functional properties and the mechanisms of interaction among different degrees of freedom in these systems. Chemical reactions at surface, such as heterogeneous catalysis, on-surface polymerization, surface and subsurface alloying as well as the stability of low-dimensional and layered materials in humid, oxidative, hydrogen or ambient environments can be also tackled thanks to the surface and chemical sensitivity of the available spectroscopic methods. More recently the X-ray- based spectroscopic techniques have been integrated on BACH beamline for the study of liquid and on the liquid/solid interfaces to enable the comprehensive understanding of the electron transfer processes during chemical reactions. This goal has been pursued by the encapsulation of fluids between a thin membrane and a solid substrate.

2D materials and interface chemical physics

Our activities in the field of 2D materials are focused on surface-assisted synthesis of doped graphene and 2D in-plane hexagonal boron nitride – graphene heterostructures. It has been only recently recognized thatheterogeneous catalysis can take place in the confined space between a solid catalyst and a weakly interacting two-dimensional (2D) overlayer. This peculiar space can be regarded as a nanoreactor, where confined molecule adsorption and surface reactions may occur. Even more enhanced catalytic performance could be exhibited by hybrid layers in which two or more materials are combined. We are examining the confinement effects and the reactions in the nanospace between an in-plane heterostructure of graphene and hexagonal boron nitride and platinum substrate. Furthermore, we have succeeded to fabricate sealed graphene nanobubbles filled with aqueous solutions between a graphene layer and a TiO2 crystal which allows us to study thermo- and photo-induced reactions.

Chemical reactions at surfaces

Tunable source of excitation energy, high-resolution XPS and soft x-ray XAS permit us to significantly enhance surface sensitivity as well as sensitivity to certain elements (e.g., nitrogen, sulfur, lithium, carbon, oxygen, chalcogens, top-most atoms). The high sensitivity to their chemical states is being exploited in the study of chemical reactions at surfaces, such as heterogeneous catalysis, on-surface polymerization, surface and subsurface alloying. We are studying growth, intercalation, and chemical reactivity of 2D materials; growth of graphene nanoribbons from halogenated molecular precursors by surface-assisted catalysis; photocatalytic reactions in nanobubbles trapped under graphene.

Transition metal dichalcogenides

Transition metal dichalcogenides (TMDC) represent a family of materials typically in the form of MX2 where M is the transition metal and X is the chalcogen (S, Se, Te). Most TMDC bulk crystals are layered solids with strong bonding within the plane but weak interlayer bonding. Dopant atoms may intercalate between layers and appropriate dopant selection and concentration can improve the performance of TMDCs. On the other hand, improper doping might have unwanted effects. Understanding the principles and mechanisms yielding the phases with desired or undesired properties is an important prerequisite to engineer materials with tailored functionalities. In collaboration with several external research groups, we study the composition and electronic structure of new TMDC materials or TMDC synthesized by novel methods.

Nanomaterials

The wide photon energy range and high-resolution XPS are very suitable for the non-destructive chemical composition depth profiling of nanostructures, such as nanoparticles and nanotubes. XPS depth profiling of such non-planar objects is not available in standard laboratory conditions, because it requires a tunable photon source. This technique has been used at BACH beamline for the chemical composition analysis of quantum dots (QD) solar cells, nanocrystals of semiconducting material which offer great potential as the light-harvesting elements in next-generation solar cells.

Spectroscopy in liquids and at liquid/solid interfaces

XPS and XAS techniques have been successfully used at BACH beamline to follow thermo- and photo-induced reactions in liquid phase. This goal has been pursued by the encapsulation of fluids between a thin membrane and a solid substrate. This research line is developing on BACH beamline following new strategies, as the use of micro electrochemical cells suitable for photocatalytic or electrochemical reactions, such as CO2RR, ORR, OER and water splitting.

 

 

 

 

 

Projects

INFRAIA-2019-1, AHEAD, 2020-2024  https://babe.iom.cnr.it/

Accordo bilaterale SAS - Slovak Academy of Sciences, 2020-2022

 

Main collaborations

  • Elettra Sincrotrone Trieste, Italy
  • Università dell’Aquila, Italy
  • Università di Palermo, Italy
  • Università degli Studi di  Padova, Italy
  •  Università degli Studi di Roma Sapienza, Italy
  • Università degli Studi  Roma 3, Italy
  • CNR-ICCOM, Firenze, Italy
  • CU Boulder, Colorado
  • Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Germany
  • University of Johannesburg, South Africa
  • Freie Universität Berlin, Germany
  • Technische Universität München TUM, Germany
  • Technische Universität Darmstadt, Germany
  •  Slovak Academy of Sciences (IEE-SAS)
  •  Russian Academy of Sciences (RAS)
  • University of Pardubice, Czech Republic
  • Materials Physics Center (CFM), San Sebastian, Spain 

Key publications

Review of Scientific Instruments, 92-1, 2021 doi:10.1063/5.0025326

Soft x-ray spectroscopies in liquids and at solid-liquid interface at BACH beamline at Elettra

Nappini S., D'Amario L., Favaro M., Dal Zilio S., Salvador F., Betz-Güttner E., Fondacaro A., Píš I., Romanzin L., Gambitta A., Bondino F., Lazzarino M., Magnano E.
Journal of Materials Chemistry C, 9-4:1235-1244, 2021 doi:10.1039/d0tc04883f

Assessing the stability of Cd<inf>3</inf>As<inf>2</inf>Dirac semimetal in humid environments: The influence of defects steps and surface oxidation

Zhang Y., Nappini S., Sankar R., Bondino F., Gao J., Politano A.
Chemical Science, 10-6:1857-1865, 2019 doi:10.1039/c8sc04461a

Under-cover stabilization and reactivity of a dense carbon monoxide layer on Pt(111)

Píš I., Magnano E., Nappini S., Bondino F.
Applied Surface Science, 479:903-913, 2019 doi:10.1016/j.apsusc.2019.01.274

Chemical composition and interaction strength of two-dimensional boron‑nitrogen‑carbon heterostructures driven by polycrystalline metallic surfaces

Nappini S., Bondino F., Píš I., Chelleri R., Greco S.L., Lazzarino M., Magnano E.
Carbon, 134:274-282, 2018 doi:10.1016/j.carbon.2018.03.086

Fe intercalation under graphene and hexagonal boron nitride in-plane heterostructure on Pt(111)

Píš I., Nappini S., Bondino F., Menteş T.O., Sala A., Locatelli A., Magnano E.
Carbon, 120:185-193, 2017 doi:10.1016/j.carbon.2017.05.026

On-surface synthesis of different boron–nitrogen–carbon heterostructures from dimethylamine borane

Nappini S., Píš I., Carraro G., Celasco E., Smerieri M., Savio L., Magnano E., Bondino F.
Nanoscale, 9-13:4456-4466, 2017 doi:10.1039/c6nr09061c

Graphene nanobubbles on TiO<inf>2</inf> for in-operando electron spectroscopy of liquid-phase chemistry

Nappini S., Matruglio A., Naumenko D., Dal Zilio S., Bondino F., Lazzarino M., Magnano E.
Advanced Functional Materials, 26-7:1120-1126, 2016 doi:10.1002/adfm.201503591

Formation of a Quasi-Free-Standing Single Layer of Graphene and Hexagonal Boron Nitride on Pt(111) by a Single Molecular Precursor

Nappini S., Píš I., Menteş T.O., Sala A., Cattelan M., Agnoli S., Bondino F., Magnano E.
Journal of Materials Chemistry A, 6-12:4966-4970, 2018 doi:10.1039/c7ta11161d

Exploring redox activity in a LiCoPO<inf>4</inf>-LiCo<inf>2</inf>P<inf>3</inf>O<inf>10</inf> tailored positive electrode for 5 v lithium ion batteries: Rigid band behavior of the electronic structure and stability of the delithiated phase

Cherkashinin G., Lebedev M.V., Sharath S.U., Hajduk A., Nappini S., Magnano E.
Journal of Physical Chemistry C, 120-9:4909-4918, 2016 doi:10.1021/acs.jpcc.5b12047

Surface-Confined Polymerization of Halogenated Polyacenes: The Case of Dibromotetracene on Ag(110)

Píš I., Ferrighi L., Nguyen T.H., Nappini S., Vaghi L., Basagni A., Magnano E., Papagni A., Sedona F., Di Valentin C., Agnoli S., Bondino F.