Alloy design has been a lifelong interest of Gareth Thomas,
and modern design algorithms include atomistic parameters which
are obtainable from new electron microscope techniques such
as ALCHEMI. In this paper, we discuss the relevance of ALCHEMI
site occupancy measurements to intermetallic alloys, and summarize
prior work. The results are found to lie in regions of a
site-occupancy diagram (SOC) relating ordering energies to
occupancy, as predicted by the Bragg–Williams theory of
short-range order. These predictions also explain previous
inconsistencies in the ALCHEMI measurements. A diffraction camera
and X-ray detector system of novel design is proposed for dedicated
ALCHEMI analysis for substitutional and interstitial dopant
site-occupancy measurement, and details of the design given.
Using this novel hardware design, the data-collection times
for two-dimensional ALCHEMI patterns should be reduced by an
order of magnitude or more, and the full data collection process
automated. The resulting occupancy information can provide
essential input parameters for atomistic alloy design algorithms,
and can provide entirely new information on interstitial
occupancies in minerals, ceramics, semiconductors, and alloys.
UAV-Enabled Data Collection: Multiple Access, Trajectory Optimization, and Energy Trade-Off
