Back to Search
Start Over
Surface valence transition in SmS by alkali metal adsorption
- Publication Year :
- 2022
-
Abstract
- The electronic structure changes of SmS surfaces under potassium (K) doping are elucidated using synchrotron-based core-level photoelectron spectroscopy and angle-resolved photoelectron spectroscopy (ARPES). The Sm core-level and ARPES spectra indicate that the Sm mean valence of the surface increased from the nearly divalent to trivalent states, with increasing K deposition. Carrier-induced valence transition (CIVT) from Sm$^{2+}$ to Sm$^{3+}$ exhibits a behavior opposite to that under conventional electron doping. Excess electrons are trapped by isolated excitons, which is inconsistent with the phase transition from the black insulator with Sm$^{2+}$ to the gold metal with Sm$^{3+}$ under pressure. This CIVT helps to clarify the pressure-induced black-to-golden phase transition in this material, which originates from the Mott transition of excitons.<br />Comment: 7 pages, 6 figures
Details
- Database :
- arXiv
- Publication Type :
- Report
- Accession number :
- edsarx.2205.15522
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1103/PhysRevB.107.L041102