LION - Kamerlingh Onnes Laboratory

ESCHER

A microscopy facility for Electronic, Structural and CHEmical Nanoimaging in Real time.

NEWS:
- The LEEM has been installed in the Kamerlingh Onnes lab!
- Opening Symposium of the Leiden Center of UltraMicroscopy
   September 17, in Leiden. See www.ultramicroscopy.nl.

Escher is a state-of-the-art spectroscopic LEEM/PEEM facility that is currently being developed at Leiden University. In May 2008, this research project was funded by the Dutch NWO-Groot Program for large investments. Escher will be an exciting set-up with a broad range of possibilities, enabling us to apply LEEM/PEEM to various fascinating research questions in surface science, nanoscience, transport physics and exploratory bioscience. We expect Escher to be running, autumn 2010.

LEEM stands for low energy electron microscopy. This imaging technique was originally developed by Ernst Bauer and later improved by Ernst Bauer, Ruud Tromp and others. In LEEM, an electron beam is first accelerated (typically to 15 keV) and focused towards a sample (see Figure). Just before the sample, however, the electrons are decelerated again, to almost zero energy (~eV). Hence, the incoming electrons can probe the sample surface with very high sensitivity. The electrons returning from the sample, are re-accelerated, focused and finally imaged. Imaging can be done in real space, as well as in reciprocal space (Low energy electron diffraction, LEED). In the Figure, we show a schematic image of Tromp's LEEM design. The electrons run from top to bottom, via the sample (green) which is at a 90^o angle.
PEEM denotes photo-electron emission microscopy. In this case, the electrons are released from the sample via the photo-electric effect, and subsequently imaged using the same electron optics as for LEEM.

We aim for a combined LEEM/PEEM instrument featuring aberration-corrected optics with < 2 nm spatial resolution, energy filtered spectroscopic real space imaging, full 3D k-space electron spectroscopy, on sub-micron length scales, and a 10-1800 K operating range. For this, we will not only build up a state-of-the-art set-up, we will also invest deeply in instrument development. Our focus is to build a low-temperature sample holder (a Leiden tradition), as well as to improve the detection technology. The scientific program will address issues in molecular and organic electronics, transport physics, surface, thin film, and interface science, novel materials, and exploratory bioscience.

For more information, please check out a recent presentation on Escher

Investigators:   Sense Jan van der Molen (PI), Ruud Tromp, Jan Aarts, Joost Frenken,

                          Jan van Ruitenbeek, Marcel Rost and Tjerk Oosterkamp

Collaborators:   Mark Golden (UvA) and Bene Poelsema/Raoul van Gastel (TU Twente)

On October 16 and 17, 2008, we organized a kick-off meeting, to bring together all scientists in and around the Netherlands who may now or later be interested in the unique ESCHER set-up. We aim for an open and inspiring meeting with plenty of discussion.

Scientific publications within ESCHER:

Medipix 2 detector applied to Low Energy Electron Microscopy

R. van Gastel, I. Sikharulidze, S. Schramm, J.P. Abrahams, B. Poelsema, R.M. Tromp, and S.J.van der Molen, Ultramicroscopy 110, 33–35 (2009)

Ruisloos deeltjes detecteren.

Raoul van Gastel, Sense Jan van der Molen, Irakli Sikharulidze, Georg Gademann, Julia Jungmann, Ron M.A. Heeren en Marc Vrakking, Nederlands Tijdschrift voor Natuurkunde 75-11, 374-377 (2009). In Dutch.

Links:                  LEEM/PEEM user page,   LEEM in Twente (NL)

Last update: 25 Aug 2010.

ESCHER A microscopy facility for Electronic, Structural and CHEmical Nanoimaging in Real time.
NEWS: - The LEEM has been installed in the Kamerlingh Onnes lab! - Opening Symposium of the Leiden Center of UltraMicroscopy September 17, in Leiden. See www.ultramicroscopy.nl.
Escher is a state-of-the-art spectroscopic LEEM/PEEM facility that is currently being developed at Leiden University. In May 2008, this research project was funded by the Dutch NWO-Groot Program for large investments. Escher will be an exciting set-up with a broad range of possibilities, enabling us to apply LEEM/PEEM to various fascinating research questions in surface science, nanoscience, transport physics and exploratory bioscience. We expect Escher to be running, autumn 2010.
LEEM stands for low energy electron microscopy. This imaging technique was originally developed by Ernst Bauer and later improved by Ernst Bauer, Ruud Tromp and others. In LEEM, an electron beam is first accelerated (typically to 15 keV) and focused towards a sample (see Figure). Just before the sample, however, the electrons are decelerated again, to almost zero energy (~eV). Hence, the incoming electrons can probe the sample surface with very high sensitivity. The electrons returning from the sample, are re-accelerated, focused and finally imaged. Imaging can be done in real space, as well as in reciprocal space (Low energy electron diffraction, LEED). In the Figure, we show a schematic image of Tromp's LEEM design. The electrons run from top to bottom, via the sample (green) which is at a 90^o angle. PEEM denotes photo-electron emission microscopy. In this case, the electrons are released from the sample via the photo-electric effect, and subsequently imaged using the same electron optics as for LEEM.
We aim for a combined LEEM/PEEM instrument featuring aberration-corrected optics with < 2 nm spatial resolution, energy filtered spectroscopic real space imaging, full 3D k-space electron spectroscopy, on sub-micron length scales, and a 10-1800 K operating range. For this, we will not only build up a state-of-the-art set-up, we will also invest deeply in instrument development. Our focus is to build a low-temperature sample holder (a Leiden tradition), as well as to improve the detection technology. The scientific program will address issues in molecular and organic electronics, transport physics, surface, thin film, and interface science, novel materials, and exploratory bioscience. For more information, please check out a recent presentation on Escher
Investigators: Sense Jan van der Molen (PI), Ruud Tromp, Jan Aarts, Joost Frenken, Jan van Ruitenbeek, Marcel Rost and Tjerk Oosterkamp Collaborators: Mark Golden (UvA) and Bene Poelsema/Raoul van Gastel (TU Twente)
On October 16 and 17, 2008, we organized a kick-off meeting, to bring together all scientists in and around the Netherlands who may now or later be interested in the unique ESCHER set-up. We aim for an open and inspiring meeting with plenty of discussion.
Scientific publications within ESCHER: Medipix 2 detector applied to Low Energy Electron Microscopy R. van Gastel, I. Sikharulidze, S. Schramm, J.P. Abrahams, B. Poelsema, R.M. Tromp, and S.J.van der Molen, Ultramicroscopy 110, 33–35 (2009) Ruisloos deeltjes detecteren. Raoul van Gastel, Sense Jan van der Molen, Irakli Sikharulidze, Georg Gademann, Julia Jungmann, Ron M.A. Heeren en Marc Vrakking, Nederlands Tijdschrift voor Natuurkunde 75-11, 374-377 (2009). In Dutch.
Links: LEEM/PEEM user page, LEEM in Twente (NL)