標題: | Electrostatic potential and valence modulation in La0.7Sr0.3MnO3 thin films |
作者: | Trappen, Robbyn Garcia-Castro, A. C. Vu Thanh Tra Huang, Chih-Yeh Ibarra-Hernandez, Wilfredo Fitch, James Singh, Sobhit Zhou, Jinling Cabrera, Guerau Chu, Ying-Hao LeBeau, James M. Romero, Aldo H. Holcomb, Mikel B. 物理研究所 Institute of Physics |
公開日期: | 25-九月-2018 |
摘要: | The Mn valence in thin film La0.7Sr0.3MnO3 was studied as a function of film thickness in the range of 1-16 unit cells with a combination of non-destructive bulk and surface sensitive X-ray absorption spectroscopy techniques. Using a layer-by-layer valence model, it was found that while the bulk averaged valence hovers around its expected value of 3.3, a significant deviation occurs within several unit cells of the surface and interface. These results were supported by first principles calculations. The surface valence increases to up to Mn3.7+, whereas the interface valence reduces down to Mn2.5+. The change in valence from the expected bulk value is consistent with charge redistribution due to the polar discontinuity at the film-substrate interface. The comparison with theory employed here illustrates how this layer-by-layer valence evolves with film thickness and allows for a deeper understanding of the microscopic mechanisms at play in this effect. These results offer insight on how the two-dimensional electron gas is created in thin film oxide alloys and how the magnetic ordering is reduced with dimensionality. |
URI: | http://dx.doi.org/10.1038/s41598-018-32701-x http://hdl.handle.net/11536/148211 |
ISSN: | 2045-2322 |
DOI: | 10.1038/s41598-018-32701-x |
期刊: | SCIENTIFIC REPORTS |
Volume: | 8 |
顯示於類別: | 期刊論文 |