ASTAR is an automatic crystallographic indexing and orientation/phase mapping tool, developed for any TEM. ASTAR can turn any TEM into a very powerful analytical tool enabling orientation/phase imaging at 1 nm resolution in combination with other analytical techniques.
Mapping the relative orientation of crystalline grains and/or phases helps understand material texture at the micro and nano scales. In a transmission electron microscope, this is accomplished by recording a diffraction pattern at a large number of points (over a region of the crystalline specimen. ED/PED spot patterns are collected sequentially with a dedicated external (CCD) camera while the sample area (that is typically tens of square micrometers) is scanned by the primary electron beam and simultaneously precessed around the optical axis of the microscope. The tool named “ASTAR“(automatic TEM phase-orientation mapping) includes precession device “DigiSTAR“. The external dedicated “fast” CCD camera (8 bit, > 150 frames/s, 250 x 250 pixels image size) is mounted in front of the TEM screen.
By comparing the recorded patterns to a database of known patterns (simulated patterns of existing known phases), the relative orientation of grains in the field of view can be determined.
TOPSPIN Strain combines Precession Electron Diffraction (PED) with automated strain mapping and analysis of diffraction patterns by comparing unstrained and strained areas in the same crystalline sample (Patent Pending). This technique gas the unique advantage of achieving high precision (0.02%) and a spatial resolution down to 3 nm (specimen dependent).
TOPSPIN strain analysis is a novel approach to strain measurement that combines NBD with precession electron diffraction to overcome the limitations. Further, Topspin strain analysis uses a robust analysis algorithm for high accuracy and precision with the ability to handle overlapping patterns.