Abstract
We determine the work functions of the iron arsenic compounds () using photoemission spectroscopy to be 2.7 eV for , 1.8 eV for , and 1.3 eV for . The work functions of these 122 iron-based superconductors track those of the elementary metal but are substantially smaller. The most likely explanation of this observation is that the cleaving surface exposes only half an -layer. The low work function and good photoemission cross section of and enable photoemission even from a common white LED light.
- Received 25 October 2019
- Accepted 13 January 2020
DOI:https://doi.org/10.1103/PhysRevMaterials.4.034801
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