FEI and CEOS announced today that they have delivered the first sub-Ångstrom, low-voltage electron (SALVE) microscope to the University of Ulm.
The microscope, equipped with a Cc/Cs-corrector from CEOS, was developed in collaboration with the University of Ulm.
It uses electrons with energies between 20keV and 80keV, much lower than typical for a transmission electron microscope (TEM), to enhance contrast and reduce radiation damage to light element samples, including two-dimensional (2D) materials like graphene and organic materials.
The system corrects both spherical and chromatic aberrations to deliver atomic-scale image resolution and reduces the energy spread of the beam with a monochromator to provide high-energy resolution spectroscopic analysis of composition, electronic structures and bonding states.
We are truly excited to receive this new tool, which is the first of its kind. Our long effort pays off. It will allow our researchers to visualize atomic structures with sub-Ångstrom spatial resolution in materials that have, until now, been difficult to investigate because of their sensitivity to damage by the electron beam and their low imaging contrast.
We believe it will open the door to ground-breaking discoveries in this important class of materials.
Prof. Ute Kaiser - head of the SALVE project, University of Ulm
We could not have developed this industry-leading microscope without the critical contributions of our partner CEOS and the close interaction with the University of Ulm. Excellent teamwork throughout the project and the early-stage development of the correction system by CEOS has allowed us to build the SALVE tool in record time, with initial results that actually exceeded the guaranteed performance specification for low-voltage TEM imaging.
In addition to outstanding imaging performance, it supports cryo-EM techniques at liquid nitrogen temperatures and provides high-resolution electron energy loss spectroscopy (EELS) information at low voltages. These capabilities will extend the range of our industry-leading Titan™ Themis TEM platform into entirely new application spaces, such as research on molecules and new 2D materials.
Bert Freitag - Product Marketing for Materials Science, FEI
We have had great success with our correctors for spherical aberration at higher voltages. Now we are seeing similar success correcting the chromatic aberrations that limit performance at lower voltages. The SALVE system uses both kinds of correction to deliver unprecedented imaging capability for some very interesting materials that have, until now, not been able to investigate with TEM in atomic resolution.
Prof. Max Haider - CEOS GmbH
Materials composed of light elements, such as carbon containing organic materials, and samples that are extremely thin, such as graphene, a 2D carbon film only one atom thick, have been resistant to investigation in electron microscopes because they interact weakly with, and are more easily damaged by, the high-energy electrons in the microscope’s electron beam.
Lower-energy beam electrons would interact more strongly and cause less damage, but the performance of conventional electron microscopes deteriorates at lower energies because small variations in energy among the individual electrons of the beam become larger relative to the average beam energy. These variations cause the electrons to focus differently, degrading resolution. The chromatic aberration corrector of the SALVE microscope corrects for these variations and permit sub-Ångstrom resolution at lower energies, generating more image contrast and reducing sample damage.
The SALVE project is funded by the German Research Society and the Ministry of Science, Research and the Arts Baden-Württemberg. For more information, please click here.