Making the most of data at hand is a challenge that the inner scientist
in all of us faces. As discussed in Chapter 10
of Nanoscale Science and
Engineering Education (2008 Amer. Sci. Publ), data on atomic periodicity in
images and diffraction patterns are no exception. Computers, and the modern
informatic science of Bayesian model-selection, can in fact make such data
on atom-scale periodicity much more accessible than it already is.
Questions explored here...
Sample puzzlers might include the following...
What secrets do the spots in that electron diffraction pattern contain?
Can the lattice-fringe image on the darkroom floor be put to use by the jury?
Where might ico-twin butterflies and bow-ties be hiding in that nano-particle pile?
Do those nanoparticle orientations provide clues to their deposition conditions?
...and what else?
We are starting this page to help illustrate how tales of problem solving
with newly-developed and mostly web-accessible tools can point the way toward
analysis of data on your specimens with help from those same tools. To start
with, for instance, we’ve developed an
ImageJ macro called 4spots to help you capture “2
spacings and an angle” from any single crystal diffraction pattern or lattice
image that comes your way.
In particular we address how transmission electron microscopes might help you
get the information that you need, and things you might do with your data like checking it
for indexability with a candidate structure.
Beyond that we’ll help you look toward:
ways to “go 3D” with your data acquisition and analysis,
detective work on hidden periodicities & picometer strains using digital darkfield
analyses intermediate between direct & reciprocal space,
Please bear with us as for the moment this page is only a stub. /pf
Update: At the beginning of Microscopy and Microanalysis 2012, I was asked to post
selected ImageJ plugins including the
manual for 4spots, and a copy of
our poster. Now that Microscopy and Microanalysis 2013 is
about to begin, expect to see a few more updates to this page in the days ahead.
Stay tuned for links, and more puzzlers (with code links) to explore, here...
What does that diffraction pattern tell you the associated crystal is NOT?
Is that lattice image of a single-crystal, or of something else?
What could possibly give rise to oval rings in a diffraction pattern?
Can single-strand DNA be used to stick Pt to slippery carbon nanotubes?
What fraction of the Pt particles in this Al2O3-glass matrix are crystalline?
How can I convert a 2-theta profile into a reciprocal-lattice map?
How would you search for "low-friction patches" on HF-dipped mica?
Help read travel diaries of the spaceships that brought our C-atoms here.
interactive talk notes
These might be good places for moderated commentary:
1 Feb 2006: to 16th International Microscopy Conference, Sopporo, Japan, Sept 3-8, 2006
Nanocrystal phase identification by lattice fringe fingerprinting: Theory and experimental proof of principle
B. Seipel, R. Bjorge, L. Noice, P. Moeck, E. Mandell, P. Fraundorf, N. D. Browning
15 Dec 2005: to 231st American Chemical Society (ACS) National Meeting, Atlanta, GA, March 26-30, 2006
Synthesis of srilankite nanowires: Compositional ordering
in nanowire structures
Marguerite N. Germain, Steven W. Buckner (SLU Chem), P. Fraundorf and E. A. Guliants (U. Dayton Res. Inst)
Nov 2005: chapter for Nanoscale science and engineering education: Issues, trends and future directions
This page is
http://www.umsl.edu/~fraundorfp/electronDetectives.html. As non-commercial tools,
the routines discussed here can make no guarantees as to their correctness for
any specific application. Although there are many contributors, the person
responsible for errors is P. Fraundorf. This site is hosted by the Department
of Physics and Astronomy (and Center for NanoScience) at the University of Missouri in St. Louis.