Jahn-Teller reconstructed surface of the doped manganites shown by means of surface-enhanced Raman spectroscopy
| Autor: | B. Damaschke, Vasily Moshnyaga, V. Bruchmann-Bamberg, S. Merten, Konrad Samwer |
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| Rok vydání: | 2019 |
| Předmět: |
Jahn-Teller
Materials science Physics and Astronomy (miscellaneous) Spintronics Jahn–Teller effect Doping 02 engineering and technology Surface-enhanced Raman spectroscopy 021001 nanoscience & nanotechnology Manganite 01 natural sciences Crystallography symbols.namesake 0103 physical sciences symbols General Materials Science Orthorhombic crystal system Thin film 010306 general physics 0210 nano-technology Raman spectroscopy |
| Zdroj: | Physical Review Materials. 3 |
| ISSN: | 2475-9953 |
| Popis: | We report direct evidence of the theoretically predicted electron-rich surface of doped perovskite manganites ${\mathrm{La}}_{0.7}{A}_{0.3}{\mathrm{MnO}}_{3}\phantom{\rule{4pt}{0ex}}(A=\text{Ca}$, Sr) by means of surface-enhanced Raman spectroscopy. The required Au nanoparticles were grown on top of thin manganite films by the metalorganic aerosol deposition technique, which provides a stable oxygen atmosphere and prevents deoxygenation effects. The acquired surface-enhanced Raman spectra of rhombohedral ${\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}{\mathrm{MnO}}_{3}$ thin films reveal the symmetry-forbidden Jahn-Teller stretching modes demonstrating the predicted symmetry breaking at the surface and fallback into the orthorhombic (Pnma) structure. This results in a unique Jahn-Teller reconstructed surface structure, which limits the capabilities of mixed-valence manganites in spintronic applications, but will be highly favorable for catalytic reactions. |
| Databáze: | OpenAIRE |
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