一号機 (Probe correction)
二号機（image correction）
The FEI Themis Z is and advanced analytical scanning/transmission electron microscope (STEM/TEM) from Thermo Fisher Scientific Company that operates between the electron energy of 60 to 300 keV with a Schottky electron emitter, an electron energy monochromator, and a 5th order probe spherical aberration corrector. The microscope is additionally equipped for chemical analysis using highly efficient and fast electron energy loss spectroscopy (EELS) and energy dispersive X-ray spectroscopy (EDS) systems.
This instrument will meet the research needs of electron imaging and chemical analysis in materials research. Specifically, the microscope enables imaging and chemical mapping in 2D and 3D at atomic or nanoscales by providing following research capabilities: 1) performing low voltage spectral analysis for molecules and single atoms using EELS, 2) conducting ultra-sensitive mapping of local bonding and oxidation states using EELS, and 3) analysis of composition and crystallographic orientation in 2D and 3D using EDS.
In addition to the acoustic enclosure that comes with the instrument, a custom-designed metal room was built around the whole microscope to ensure proper cancellation of electromagnetic fields that would negatively affect the performance of the instrument. The structure, called MuROOM, from Magnetic Shield Co., uses metal layers including a nickel-iron alloy sheet to shield fields that would affect, for instance, the high energy resolution required for the analytical capabilities of the instrument. The MuRoom was featured in this article.
Feature Highlights:
Acoustic enclosure and remote operation, enabling acoustic and temperature variation damping during operation
Accelerating voltage: 60 -300 kV
Electron source: High brightness Schottky field emission electron source (X-FEG)
Integrated electron source energy monochromator for beam energy widths to <150meV
Probe forming optics include an advanced 4th order (5th order optimized) spherical aberration corrector (DCOR)
Probe corrector tunings at 60, 80, and 300 kV
STEM resolution: ranging from <60pm at 300kV to <120pm at 60 kV
Greater than 100 pA probe currents available in a 1 angstrom electron probe
High Angle Annular Dark Field (HAADF) detector and on-axis bright field/dark field STEM detector
Integrated Differential Phase Contrast (iDPC) for light element (low Z) imaging
Simultaneous collection of BF/ABF/DF and HAADF images on the system
TEM mode: information transfer of 60pm at 300kV to 100pm at 60kV
Gatan Quantum ER/965 GIF with Ultrafast Dual EELS (Electron Energy Loss Spectroscopy) Spectrum Imaging (1000 spectra/s, energy resolution of 150 meV or better)
4-crystal EDS (Energy Dispersive Spectroscopy for X-Rays) detection system (FEI Super-X)
Large EDS collection solid angle of 0.7 steradians for atomic scale EDS analysis
EDS compatible with large sample rotation/tilt for 3D EDS tomography
Constant power magnetic lenses enabling faster mode and accelerating voltage changes switching by eliminating related thermal drift and providing high controllability and reproducibility
Automated tuning for the monochromator and corrector (OptiMono & OptiSTEM+)
Computerized 5-axes Piezo enhanced stage
High-speed, digital search-and-view camera
FEI Ceta 16M 16-megapixel digital camera for for imaging and diffraction applications
STEM & TEM tomography acquisition software and high field-of-view single-tilt tomography holder
Precession electron diffraction