Tecnai TF-20: 200 kV TEM, STEM, EDS, EELS, EFTEM & Lithography

From the KNI Lab at Caltech
Jump to navigation Jump to search
Tecnai TF-20
10-fold-Rotation-Axis-Quasicrystal Jinping-Hu.jpg
Instrument Type Microscopy, Lithography
Techniques TEM, STEM,
Bright & Dark Field Imaging,
Electron Diffraction,
Staff Manager Guy A. DeRose, PhD
Staff Email derose@caltech.edu
Staff Phone 626-395-3423
Reserve time on FBS
Request training via FBS User Dashboard
Lab Location B203C Steele
Lab Phone 626-395-1543
Manufacturer FEI (now Thermo Fisher)
Model Tecnai TF-20


A schematic of the KNI's Tecnai TF-20 TEM/STEM. Modified from an original schematic that is courtesy of Portland State University.

The Tecnai TF-20 is a transmission electron microscope (TEM) that can also be operated in scanning transmission electron microscopy (STEM) mode, with a voltage range of 40 to 200 kV. The TF-20 is equipped with bright field, dark field, and secondary electron detectors for use in STEM mode, an energy dispersive spectroscopy (EDS) detector for compositional analysis (in both TEM mode and, most often, in STEM mode), electron energy loss spectroscopy (EELS) & energy-filtered TEM (EFTEM), and a nanometer pattern generating system (NPGS) for performing lithography. Note that the KNI also has a 300 kV TEM, the Tecnai TF-30, which achieves higher resolution (albeit with fewer analytical options). See a full list of training and educational resources for this instrument below.

  • High-Resolution TEM (HRTEM) imaging without an objective aperture
  • Bright Field (BF) & Dark Field (DF) imaging with an objective aperture
  • Selected Area Electron Diffraction (SAED)
  • STEM imaging with a BF, DF & Secondary Electron (SE) detector
  • Energy Dispersive Spectroscopy (EDS) with an EDAX Genesis system
  • Electron Energy Loss Spectroscopy (EELS) & Energy-Filtered TEM (EFTEM)
  • E-beam lithography with Nanometer Pattern Generating System (NPGS) software


Equipment Data
SOPs & Troubleshooting
Manufacturer Resources
  • Full manufacturer manual is accessible via the UI under the Help menu
Other Online Resources
Sample Preparation
  • Sample preparation is a highly specific task related to each sample type and is therefore primarily the responsibility of the user to carry out.
    • KNI staff can teach users how to create lamellae from a bulk specimen using an SEM/Ga-FIB system (see SOP and YouTube playlist)
    • The KNI also has a TEM sample preparation lab that is primarily used to make cross-section samples by traditional methods (i.e. glue together a stack, cut out 3 mm core, thin by polishing, dimple, then final polish with argon mill); inquire with staff for help with these sample preparation tools
Order Your Own Grids
  • Grids used for mounting specimens are considered a personal, consumable item in the KNI. You are required to supply your own grids.


Manufacturer Specifications
TEM & STEM Specifications
  • From FEI’s (now Thermo Fisher’s) Tecnai G2 20 Family
  • Voltage Range: 80-300 kV
  • Point resolution: 0.27 nm
  • Line resolution: 0.144 nm
  • STEM resolution: 1.0 nm
  • Information limit: 0.18 nm
  • Energy spread: 0.7 eV
  • Max alpha-tilt angle with double-tilt holder: ±50°
  • Maximum diffraction angle: ±10°
  • Camera length: 35–2300 mm
  • EDS solid angle: 0.13 srad

Related Instrumentation in the KNI

Transmission Electron Microscopes
Sample Preparation for TEM
Scanning Electron Microscopes (SEMs)
Focused Ion Beam (FIB) Systems
Sample Preparation for Microscopy