Gold support suppresses stripe formation in an atomically thin material
A peer-reviewed study found that gold-supported single layers of iridium ditelluride avoided the low-temperature stripe ordering associated with paired iridium atoms. Microscopy, electronic measurements and calculations point to electronic coupling with gold as the main stabilizing influence. The result concerns a specific material and support: the model represents local regions rather than every alignment on polycrystalline gold.
Science··Midday
Gold-supported layers avoid stripe ordering
Single layers of iridium ditelluride on gold retained a structure without the low-temperature stripes formed by paired iridium atoms. The peer-reviewed experimental and computational study examines how the supporting surface helps determine an atomically thin material’s phase. Gold-assisted separation yielded large monolayer flakes. The same support that made those thin samples obtainable also interacted with their electronic structure, linking sample preparation to the phase observed.[1]
Microscopy and electronic measurements test the layer
The team examined atomic structure with scanning tunnelling microscopy and electronic bands with angle-resolved photoemission spectroscopy. Calculations compared a free layer with one resting on gold. The supported samples lacked a major reconstruction into stripes at very low temperatures. Much of their low-energy electronic behaviour resembled the calculated free layer, but strain and mixing between electronic orbitals in gold and the monolayer introduced changes.[1]
Electronic coupling stabilizes the model
Strain reduced the instability in the calculations but did not fully stabilize the layer by itself. Adding electronic coupling to gold gave a stable structure consistent with the missing stripes. The authors attribute the stabilization chiefly to this electronic interaction. Different alignments occur locally on polycrystalline gold, and the model does not capture every region. The finding concerns this material and support; the experiments did not demonstrate a finished device.[1]
