Valence characterisation of the subsurface region in
| Autor: | M. Thees, Chul-Hee Min, Friedrich Reinert, P. Lutz, Boyoun Kang, Thiago R. F. Peixoto, Beongki Cho |
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| Rok vydání: | 2016 |
| Předmět: |
Surface (mathematics)
Valence (chemistry) Materials science Samarium hexaboride Relaxation (NMR) 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Spectral line Adsorption Chemical physics 0103 physical sciences 010306 general physics 0210 nano-technology Anderson impurity model Surface states |
| Zdroj: | Philosophical Magazine. 96:3307-3321 |
| ISSN: | 1478-6443 1478-6435 |
| DOI: | 10.1080/14786435.2016.1192724 |
| Popis: | Samarium hexaboride (SmB6), which lies in the mixed valence regime in the Anderson model, has been predicted to possess topologically protected surface states. The intensive investigations on SmB6 have brought up the long standing questions about the discrepancy between the surface and bulk electronic properties in rare-earth compounds in general. Here, we investigate and eventually clarify this discrepancy in the particular case of SmB6 by the photoemission core-level spectra. We focus on the change in both Sm and B states depending on time, temperature, probing depth, and surface termination on the cleaved (100) surface. Our spectra show that the unusual time-dependent change in the Sm valence occurs within a period of hours, which is not related to the adsorption of residual gases. Moreover, we observe a reduction of the surface feature in the B and Sm states on the same timescale accompanied by the formation of a subsurface region. Thus, it indicates the relatively slow charge redistribution between the surface and subsurface regions. Our findings demonstrate that the f states is strongly involved in the surface relaxation. |
| Databáze: | OpenAIRE |
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