| Autor: |
Wang, Gaomin, Wang, Zhen, Meng, Meng, Saghayezhian, Mohammad, Chen, Lina, Chen, Chen, Guo, Hangwen, Zhu, Yimei, Plummer, Ward, Zhang, Jiandi |
| Rok vydání: |
2019 |
| Předmět: |
|
| Zdroj: |
Phys. Rev. B 100, 155114 (2019) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevB.100.155114 |
| Popis: |
Metallic oxide SrVO3 represents a prototype system for the study of the mechanism behind thickness-induced metal-to-insulator transition (MIT) or crossover in thin films due to its simple cubic symmetry with one electron in the 3d state in the bulk. Here we report a deviation of chemical composition and distortion of lattice structure existing in the initial 3 unit cells of SrVO3 films grown on SrTiO3 (001) from its bulk form, which shows a direct correlation to the thickness-dependent MIT. In-situ photoemission and scanning tunneling spectroscopy indicate a MIT at the critical thickness of ~3 unit cell (u.c.), which coincides with the formation of a (root2Xroot2)R45 surface reconstruction. However, atomically resolved scanning transmission electron microscopy and electron energy loss spectroscopy show depletion of Sr, change of V valence, thus implying the existence of a significant amount of oxygen vacancies in the 3 u.c. of SrVO3 near the interface. Transport and magneto-transport measurements further reveal that disorder, rather than electron correlations, is likely to be the main cause for the MIT in the SrVO3 ultrathin films. |
| Databáze: |
arXiv |
| Externí odkaz: |
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