© 2025 The Authors. Published by Elsevier Ltd.
Spectroscopy|
Spectroscopy (draft)
Spectroscopy
The kinetic energy of electrons emitted from atomic core levels after x-ray photo absorption is characteristic of the respective element and its chemical state, giving rise to individual spectral lines which can be used, e.g., to distinguish different oxidation states with XPS. Combined chemical and structural information are contained in so-called LEEM-IV measurements, where, in a separate experimental setup, low-energy electron reflectivity is recorded as a function of the incident electron energy. Such chemical and structural surface phases can be identified with a lateral resolution of a few tens of micrometers.
Complementary, the vibrational and structural properties of samples can be investigated using Raman and circular dichroism spectroscopy setups.
What kind of result do I get?
With XPS and LEEM both the chemical composition as well as the local structure and morphology of samples can be addressed. Since both techniques employ electrons with rather low energy, the information depth is restricted to a few atomic layers, and a decent electrical conductivity of the samples is required as well as ultra-high vacuum compatibility. Spectra and images can also be taken at elevated temperatures as well as during gas dosing (up to 10-4 mbar) to study changes of the chemistry, structure, and morphology during annealing or interaction with gases.
The local bonding geometry can be revealed with vibrational (Raman) spectroscopy. Circular dichroism spectroscopy (CDS) allows for the investigation of chiral structures, e.g. biomolecules adsorbed at interfaces. Both methods, Raman and CDS, are less surface sensitive than the electron-based methods of XPS and LEEM, and can be obtained from a wider class of specimens (e.g. insulators, non-UHV compatible materials.)
Principal Investigator
Prof. Dr. Jens Falta
Instrument Manager
Dr. Guilherme Dalla Lana Semione
University of Bremen
MAPEX Core Facility for Materials Analytics
TAB Building, Room 3.34
Am Fallturm 1, D-28359 Bremen
E-Mail: Instrument manager
Our key instruments
© Torben Rohbeck / Universität Bremen
Omicron DAR 400 + EA 125
X-ray photoemission spectrometer
- Twin Al/Mg anode, 125 mm hemispherical analyzer, 7-channel parallel detection unit
- UHV system additionally equipped with low-energy electron diffraction (LEED), scanning tunneling microscope (STM), and evaporation ports
© Torben Rohbeck / Universität Bremen
SPE-LEEM Elmitec
Spectroscopic low-energy electron microscope
- Full-field electron microscope with lateral resolution down to 10 nm; diffraction mode for micro-LEED images from selected areas with down to 250 nm in diameter
- Hemispherical energy analyzer
- Video rate imaging for real-time investigations, e.g., during material deposition or gas dosing; 100-1800 K temperature range
© M. Mangir Murshed / Universität Bremen
Horiba LabRAM Aramis
Raman Spectrometer
- 532 nm, 633 nm and 785 nm lasers
- Measurements possible between 78 K and 1773 K
© Monika Michaelis / Universität Bremen
Applied Photophysics Chirascan
Circular dichroism spectrometer
- Surface and interface characterization
- (Secondary) structure detection of biomolecules
More available instruments
Current instrumentation belonging to MAPEX-CF can be found in the Instrument Database of the MAPEX Center for Materials and Processes.
A click on the logo will lead you to the database.
© 2024 IOP Publishing Ltd
Spectroscopy| Electron Microscopy|
Atomic vs. sub-atomic layer deposition: impact of growth rate on the optical and structural properties of MoS₂ and WS₂
© 2024, Author(s). This article is distributed under a Creative Commons Attribution (CC BY) license.
X-Ray Diffraction| Spectroscopy| Surface Analytics| Electron Microscopy|
Growth, catalysis, and faceting of α-Ga₂O₃ and α-(InₓGa₁₋ₓ)₂O₃ on m-plane α-Al₂O₃ by molecular beam epitaxy
© 2023 The authors. Advanced Engineering Materials published by Wiley-VCH GmbH
3D Materials Analytics| Spectroscopy|
Gold Nanoparticle-Coated Bioceramics for Plasmonically Enhanced Molecule Detection via Surface-Enhanced Raman Scattering
© Reprinted with permission from ACS Appl. Nano Mater. 2022, 5, 12, 17702–17710. Copyright 2022 American Chemical Society.
In-situ, real-time investigations| Spectroscopy|
Growth Mechanism of Single-Domain Monolayer MoS₂ Nanosheets on Au(111) Revealed by In Situ Microscopy: Implications for Optoelectronics Applications
© Reprinted with permission from the Journal of Physical Chemistry C 2022 126 (45), 19101-19112. Copyright 2022 American Chemical Society.
In-situ, real-time investigations| Spectroscopy|
Phase Separation within Vanadium Oxide Islands under Reaction Conditions: Methanol Oxidation at Vanadium Oxide Films on Rh(111)
© 2022 The Authors. Published by Elsevier Ltd on behalf of European Ceramic Society.
Spectroscopy|
Plasmonic porous ceramics based on zirconia-toughened alumina functionalized with silver nanoparticles for surface-enhanced Raman scattering
© 2021 The Authors. Journal of the American Ceramic Society published by Wiley Periodicals LLC on behalf of American Ceramic Society
Spectroscopy|
Structural, vibrational, thermal, and magnetic properties of mullite-type NdMnTiO₅ ceramic
© 2021 Walter de Gruyter GmbH, Berlin/Boston
X-Ray Diffraction| Spectroscopy|
Thermal anomalies and phase transitions in Pb₂Sc₂Si₂O₉ and Pb₂In₂Si₂O₉
© 2021 The Authors. Published by American Chemical Society
In-situ, real-time investigations| Spectroscopy|
Structural Transitions Driving Interface Pulses in Methanol Oxidation on Rh(110) and VOₓ/Rh(110): A LEEM Study
© This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).
Spectroscopy|
The Transition From MoS₂ Single-Layer to Bilayer Growth on the Au(111) Surface
© 2020 Nature Scientific Reports
Spectroscopy|
The morphology of VO₂/TiO₂(001): terraces, facets, and cracks
© Copyright 2020 American Chemical Society
X-Ray Diffraction| Spectroscopy|
KLi₂RE(BO₃)₂ (RE = Dy, Ho, Er, Tm, Yb, and Y): Structural, Spectroscopic, And Thermogravimetric Studies on a Series of Mixed-Alkali Rare-Earth Orthoborates
© 2020 Elsevier B.V. All rights reserved
Spectroscopy|
Adsorption of sulfur on Si(111)
© 2019 American Chemical Society
Spectroscopy|
Controlling the Multiscale Structure of Nanofibrous Fibrinogen Scaffolds for Wound Healing
© 2017 Physical Chemistry Chemical Physics
Spectroscopy|
Growth and structure of ultrathin praseodymium oxide layers on ruthenium (0001)
© Jens Falta / Universität Bremen
Spectroscopy|