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FE-LEEM/PEEM P90 NAP

High Pressure LEEM/PEEM System with up to 1 mbar Operational Pressure.

The SPECS FE-LEEM/PEEM P90 NAP system is a fully equipped UHV analysis system for modern surface microscopy. All systems are design and manufactured at the SPECS headquarter in Berlin. A special engineering group personally accompanies the system process from the order placing until the final acceptance. Our engineers are dedicated to highest quality and usability of the system during design, testing and setup on site. Once the system is in full operation a professional service team in our HQ and our worldwide branch offices takes care of a smooth and stable operation.

Low Energy Electron Microscopy and Photoelectron Emission Microscopy are the only electron microscopic methods that are really sensitive to the topmost layer of the surface. In combination with the spectroscopic information it is a unique tool for the characterization of dynamic processes at surfaces, like surface reactions. Often the pressure range of standard LEEM/PEEM is not sufficient. Furthermore solid/vapor and liquid/vapor interfaces are omnipresent in nature and the basis for important applications. Thus, investigations at near ambient pressure (NAP) conditions are a key to understanding processes at these interfaces. Analysis techniques like NAP-XPS can work at gas pressures orders of magnitude higher than typical ultra high vacuum conditions. Near Ambient Pressure LEEM and PEEM (NAP-LEEM/PEEM) is the new addition to the tool box, finally allowing for microscopic operando studies under NAP conditions down to the nanoscale.

KEY FEATURES

  • Working pressures from UHV up to Near Ambient Pressure conditions up to 1 mbar
  • Sample temperatures up to 1000 °C
  • Lateral resolution <30 nm 
  • Integrated imaging energy filter
  • Cold field emission gun for LEEM 

MADE FOR THESE METHODS

2

PUBLICATIONS

  1. (2021) <p>Stacking Relations and Substrate Interaction of Graphene on Copper Foil</p>

    The crystallinity of graphene flakes and their orientation with respect to the Cu(111) substrate are investigated by means of low-energy electron microscopy (LEEM). The interplay between graphene and the metal substrate during chemical vapor deposition (CVD) introduces a restructuring of the metal surface into surface facets, which undergo a step bunching process during the growth of additional layers. Moreover, the surface facets introduce strain between the successively nucleated layers that follow the topography in a carpet-like fashion. The strain leads to dislocations in between domains of relaxed Bernal stacking. After the transfer onto an epitaxial buffer layer, the imprinted rippled structure of even monolayer graphene as well as the stacking dislocations are preserved. A similar behavior might also be expected for other CVD grown 2D materials such as hexagonal boron nitride or transition metal dichalcogenides, where stacking relations after transfer on a target substrate or heterostructure could become important in future experiments.



    P. Schädlich, F. Speck, C. Bouhafs, N. Mishra, S.Forti, C. Coletti, and T. Seyller
    Adv. Funct. Mater, Volume 8, Issue 7, April 9, 2021, 2002025
    Read more
  2. (2020) <p>Silicon Carbide Stacking-Order-Induced Doping Variation in Epitaxial Graphene</p>

    Generally, it is supposed that the Fermi level in epitaxial graphene is controlled by two effects: p-type polarization doping induced by the bulk of the hexagonal silicon carbide (SiC)(0001) substrate and overcompensation by donor-like states related to the buffer layer. The presented work is evidence that this effect is also related to the specific underlying SiC terrace. Here a periodic sequence of non-identical SiC terraces is fabricated, which are unambiguously attributed to specific SiC surface terminations. A clear correlation between the SiC termination and the electronic graphene properties is experimentally observed and confirmed by various complementary surface-sensitive methods. This correlation is attributed to a proximity effect of the SiC termination-dependent polarization doping on the overlying graphene layer. These findings open a new approach for a nano-scale doping-engineering by the self-patterning of epitaxial graphene and other 2D layers on dielectric polar substrates.



    D. M. Pakdehi, P. Schädlich, T. T. N. Nguyen, A. A. Zakharov, S. Wundrack, E. Najafidehaghani, F. Speck, K. Pierz, T. Seyller, C. Tegenkamp, and H. W. Schumacher
    Adv. Funct. Mater, Volume 30, Issue 45, November 4, 2020, 2004695
    Read more
  3. (2015) <p>Low-Energy Electron Potentiometry: Contactless Imaging of Charge Transport on the Nanoscale</p>

    Charge transport measurements form an essential tool in condensed matter physics. The usual approach is to contact a sample by two or four probes, measure the resistance and derive the resistivity, assuming homogeneity within the sample. A more thorough understanding, however, requires knowledge of local resistivity variations. Spatially resolved information is particularly important when studying novel materials like topological insulators, where the current is localized at the edges, or quasi-two-dimensional (2D) systems, where small-scale variations can determine global properties. Here, we demonstrate a new method to determine spatially-resolved voltage maps of current-carrying samples. This technique is based on low-energy electron microscopy (LEEM) and is therefore quick and non-invasive. It makes use of resonance-induced contrast, which strongly depends on the local potential. We demonstrate our method using single to triple layer graphene. However, it is straightforwardly extendable to other quasi-2D systems, most prominently to the upcoming class of layered van der Waals materials.



    J. Kautz, J. Jobst, C. Sorger, R. M. Tromp, H. B. Weber und S. J. van der Molen
    Scientific Reports volume 5, Article number: 13604 (2015)
    Read more

SPARE PARTS

10
Product image
Product description
Article No.
 
Gasket Helicoflex for LEEM Sample chamber

Special gasket for LEEM/PEEM sample chamber.

2060004567
Isolation tube sample holder LEEM

Isolation tube for LEEM/PEEM sample holder

2055001665
Nose insert 1 mm for objective lens

1 mm nose insert for LEEM/PEEM transfer objective lens

2055001905
Sample holder cap spares set

Spare part set for LEEM/PEEM sample holder cap

2055006884
Sample holder cap, Mo, 4 mm

4 mm Molybdenium sample holder cap for LEEM/PEEM

2055019253
Sample holder cap, Mo, 5 mm

5 mm Molybdenium sample holder cap for LEEM/PEEM

2055001664
Sample holder LEEM

LEEM/PEEM sample holder

2055017420
Sample holder LEEM-Aarhus

Only suitable for systems in combination of LEEM/PEEM and Aarhus STM

2100004650
Short-arc Hg halogen lamp, 100 W

Replacement Halogen Lamp for LEEM/PEEM

2060004220
Socket mount for sample holder LEEM

Socket mount for sample holder LEEM

2055001652

DOWNLOADS

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