Where's Waldo's Bowtie?

To see what individual bowtie crystal pairs associated with icosahedrally twinned fcc crystals look like in a darkfield decomposition array, consider first this 32x32 array of darkfield images from a 20-crystal Pd nano-particle formed by solid state reduction of Pd salts in a polymer matrix, as viewed down one of it's 10-fold symmetry axes...

Although this set of darkfield amplitude images (with the brightfield image in the center) does not separately represent all of the diffraction spots in the 10-fold symmetric image power spectrum, it does this for quite a few of them. The small angle "bowties" represent crystal pairs associated with Pd (200) and (220) lattice spacings (1.945 and 1.375 A in size), while the large angle bowties (or "butterflies") represent Pd (111) spacings (2.246 A in size) shared by pairs of bowties interfaced along a common boundary.

With this information in hand, now consider the 32x32 darkfield array from a large randomly-oriented metal cluster provided by Max Bertino at UM-Rolla. At least one well-defined bowtie resides therein, whose lattice indexing we are currently in the process of investigating for consistency with the icosahedral model above. Can you find it?


Copyright Information: This page contains excerpts from work in progress involving numerous collaborators, including Jon Bailey at UM-StL, and Max Bertino and Carmen Doudna at UM-Rolla. For simplicity, one may consider the contents of this page Copyright (...2001) by P.Fraundorf at UM-StL. Until primary elements of this have been published in a journal or preprint archive, we ask that you consult with us before sharing information on, or about, this page with others.