Growth, morphology, and structure of a monolayer thick GdFe2 surface alloy
journal contributionposted on 2018-05-01, 08:49 authored by R. P. Williams, S. G. Alcock, Paul B. Howes, C. L. Nicklin
The growth and structure of an ordered GdFe2 surface alloy deposited on Mo(110) has been studied using in situ surface x-ray diffraction. Growth curves and reflectivity scans of varying ratios of Gd to Fe show how the two species intermix prior to alloy formation. After annealing to form the ordered surface alloy, in-plane x-ray diffraction data indicate that the Fe atoms are laterally displaced along the  or [00¯1] direction by 0.16±0.02 Å from the long bridge site positions. Out-of-plane crystal truncation rod analysis reveals that the Gd atoms lie 3.40±0.09 Å above the Mo(110) bridge site, an expansion of 22% relative to the expected hard sphere distance. This is significantly larger than observed in previous studies of the growth of pure Gd on Mo(110). Simple geometric changes are not able to account fully for this expansion and we propose that hydrogen incorporation during alloy formation may also contribute.
CitationPhysical Review B, 2016, 94, 075419
Author affiliation/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy
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