Publication
Complex-Color Darkfield TEM Interfaces for Crystal, Defect, & Strain Analysis
Complex-color darkfield TEM imaging in real-time is now possible with modern scopes & simulators, yielding visceral access to lattice defect & strain maps.
What is it about?
Transmission electron-microscopy (TEM) involves the effective use of electron-optics plus an understanding of beam-specimen interactions, along with insight into the structure of your particular specimen including the consequences of specimen-preparation (for better or worse). Computer support for these characterization tasks is also evolving rapidly. However instrument time for both operator-training and interface-development is limited and quite expensive.
Following on some analytical work about image contrast transfer and lattice fringe visibility, here we discuss the potential of strong phase/amplitude-object simulations, with help from Javascript/HTML5-canvas on modern devices, to serve up an on-line mobile-friendly platform for TEM operator-training and analytical-TEM software-interface development. The simulator that we make available has already been put to use with students in many nanoscience practicals classes, and makes available real-time digital-darkfield tools useful with both deBroglie phase-contrast (e.g. HRTEM) and incoherent amplitude-contrast (e.g. HAADF-STEM) lattice-images.
Why is it important?
Real time simulation can be used to improve interfaces to modern electron and scanning probe microscopes, for access to emerging strategies, as well as for training scientists and operators in their use. For transmission electron microscopes, strong phase object (single-slice) simulations already offer real-time access, at least for modest sized images.
Perspectives
On-line simulators for microscopy training are already becoming available, as in the case e.g. of Microscopy Australia's excellent "MyScope" site. Such simulators can also be used to introduce emerging techniques for both training, and development of real-time interfaces on next-generation microscopes. The use of log-complex color to display a wide range of complex (real + imaginary) values with a single pixel is a case in point. This is key to a whole family digital darkfield methods, which historically have not been available to TEM operators in real-time. Look for extension of tools like this to other types of instruments, and analytic approaches, in the days ahead!
