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Simple metal under tensile stress: layer-dependent herringbone reconstruction of thin potassium films on graphite

Research output: Contribution to journalArticleScientificpeer-review

Details

Original languageEnglish
Article number10165
Number of pages8
JournalScientific Reports
Volume5
DOIs
Publication statusPublished - 11 May 2015
Publication typeA1 Journal article-refereed

Abstract

While understanding the properties of materials under stress is fundamentally important, designing experiments to probe the effects of large tensile stress is difficult. Here tensile stress is created in thin films of potassium (up to 4 atomic layers) by epitaxial growth on a rigid support, graphite. We find that this "simple" metal shows a long-range, periodic "herringbone" reconstruction, observed in 2- and 3- (but not 1- and 4-) layer films by low-temperature scanning tunneling microscopy (STM). Such a pattern has never been observed in a simple metal. Density functional theory (DFT) simulations indicate that the reconstruction consists of self-aligned stripes of enhanced atom density formed to relieve the tensile strain. At the same time marked layer-dependent charging effects lead to substantial variation in the apparent STM layer heights.

Keywords

  • SUBMONOLAYER POTASSIUM, ELECTRONIC-STRUCTURE, PHASE-TRANSITIONS, POST-PEROVSKITE, HIGH-PRESSURE, GRAPHENE, CLUSTERS, SURFACE, NANOSCALE, PHYSICS

Publication forum classification

Field of science, Statistics Finland