Task:
- Investigation of basic structural and electronic properties of solid state materials and devices on the atomic scale by analytical and in situ transmission electron microscopy
Specific information on the method:
- High Resolution (scanning) Transmission Electron Microscopy (HR(S)TEM)
- Energy Dispersive X-ray Spectroscopy (EDXS)
- Electron Energy Loss Spectroscopy (EELS)
- High Angle Annular Dark Field (HAADF) Imaging
Specific information on the equipment/instrumentation: The FEI Titan G2 80-200 CREWELEY is a remotely operated field emission gun (scanning) transmission electron microscope equipped with a high-brightness Schottky field emission electron gun, a monochromator unit, a Cs probe corrector, a Super-X EDX system, an UltraScan 1000XP-P charge coupled digital camera, an on-axis bright-field/dark-field STEM detector as well as a Gatan Enfinium ER (model 977) spectrometer with DUAL EELS option allowing a simultaneous read-out of EDX and EELS signals at a speed of 1000 spectra per second. Basic specifications for the instrument are given below.
Basic specifications | |
Acceleration voltage | 80 kV … 200 kV |
X-FEG brightness (200 kV) | 1.8 E9 A cm-2 sr-1 |
Information limit (TEM @ 200 kV) | 1.1 Å |
Point resolution (TEM @ 200 kV) | 2.4 Å |
Combined image and sample drift (TEM @ 200 kV) | < 0.3 nm/min |
Astigmatism instability (TEM @ 200 kV) | < 0.6 nm/min |
Resolution (STEM @ 200 kV and 50 pA) | 0.8 Å |
EDX system energy resolution (10 kcps) | < 136 eV @ MnKa |
EDX solid angle | 0.9 sr |
Combined electron probe and sample drift | < 0.3 nm/min |
EELS system energy resolution (120 and 200 kV) | 0.65 eV |
Detectors | |
Gatan UltraScan 1000XP-P (2k x 2k) charge coupled device camera | |
Fischione HAADF STEM detector | |
On-axis triple DF1/DF2/BF detectors | |
FEI Super-X EDX system with 120 mm2 combined detector area | |
Gatan Enfinium ER (model 977) EEL spectrometer | |
Specimen stages | |
Double tilt low background holder | ± 35° |
Specimen drift DTLBH | cf. above |
High field of view single tilt tomography holder | ± 70° |
Further biasing, cooling and heating holders for in situ TEM experiments |
Samples/limitations:
Measurements making use of the instrument can be performed on a wide bunch of condensed matter samples with the exception of biological, cryogenic, ferromagnetic, polymeric or water-based samples. Experiments on contaminated, antiferromagnetic or paramagnetic samples might be carried out in consulting with the instrument officers as well as the radiation protection officer and the general manager of the ER-C (all three of them).
Examples of typical analytical questions:
– Two dimensional mapping of the composition in solids and devices by energy dispersive X-ray spectroscopy (EDXS) and electron energy loss spectroscopy (EELS)
– Analysis of diffusion process driven compositional intermixing phenomena at heterointerfaces in electro ceramics, metals and semiconductors
– Atomic scale analysis of crystallographic phases and lattice defects in crystalline solids
– Investigation of stoichiometric changes of materials and devices upon thermal treatment.
Fields of research:
The instrument is intended to be used for the investigation of basic solid state research phenomena on the atomic scale in electro ceramics, metals, semiconductors, superconductors with an application potential in energy research and information technology.
Access and Contact:
Access to the instrument is via the regular access mechanisms of the ER-C outlined in detail at www.er-c.org/centre/proposal.htm
Dr. András Kovács (instrument officer ER-C)
Dr. Roland Schierholz (deputy instrument officer IEK-9)
Werner Pieper (radiation protection officer ER-C)
Dr. Karsten Tillmann (general manager ER-C)