The aim of the UHRTEM laboratory of the LMA is to offer the scientific community access to unique instruments and expertise allowing the structural and chemical analysis of materials at a spatial resolution of few picometers. With that purpose, the UHRTEM laboratory is equipped with the very last generation of Transmission Electron Microscopes (TEM).
Two “dedicated” Cs-corrected TEMs:
A TITAN STEM microscope dedicated to EELS and STEM HAADF studies.
This Scanning Transmission Electron Microscope works either in TEM or in STEM mode at voltages between 60 kV and 300 kV. It then can be used at low voltage to analyse electron irradiation sensitive materials. It is fitted with the last generation of a high brightness Schotky emitter developed by FEI (the so called “X-FEG” gun) a monochromator and a Gatan 2k x 2k CCD camera.
STEM: As this microscope is devoted for STEM and EELS experiments, it is equipped with a CETCOR Cs-probe corrector from CEOS Company allowing for the formation of an electron probe of 0.08 nm mean size. The TEM is equipped with all the STEM facilities (BF, DF, ADF and HAADF detectors) and 0.08 nm spatial resolution has indeed been achieved in STEM-HAADF mode.
EELS and EDS: For EELS experiments, the microscope is fitted with a Gatan Energy Filter Tridiem 866 ERS and a monochromator. An energy resolution of 0.14 eV has been recently achieved with this setup. In addition, an EDS (EDAX) detector allows performing EDX experiments in scanning mode with a spatial resolution of about ~0.2 nm.
Lorentz and holography: Beside these analytical capabilities, the Titan STEM corrected microscope is fitted with a Lorentz lens and an electrostatic biprism allowing Lorentz and medium resolution electron holography experiments to be carried out in a field-free environment (as needed for magnetic materials studies). Tomography: In addition, a tomography set-up with a +/- 70° single tilt stage permits to perform 3D analyses either in TEM or STEM modes.
A TITAN3 microscope dedicated to Ultra High Resolution TEM imaging
This TEM also works at voltages between 60 and 300 kV. It is located in a “box” (cube) to avoid mechanical and thermal perturbation (see figure). It contains a normal FEG (Shottky emitter) and a Gatan 2k x 2k CCD camera for (HR)TEM images acquisition.
HRTEM: As this microscope is devoted for High Resolution Transmission Electron Microscopy (HRTEM) studies, it is equipped with a SuperTwin® objective lens and a CETCOR Cs-objective corrector from CEOS Company allowing a point to point resolution of 0.08 nm.
STEM: In addition this Titan3 is equipped with the basic STEM facilities (BF, DF detectors) for STEM imaging at medium resolution.
EELS: a Gatan Energy Filter Tridiem 863 allows Titan3 to perform EELS experiments in a standard and routine way (energy resolution of ~0.7 eV).
Lorentz and holography: As for the dedicated Titan STEM, beside these spectroscopy capabilities, the Titan3 corrected microscope is fitted with a Lorentz lens and an electrostatic biprism allowing Lorentz and medium resolution electron holography experiments to be carried on.