A Living-Dead Magnetic Layer at the Surface of Ferrimagnetic DyTiO3 Thin Films
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
| Veröffentlicht in: | Advanced materials (Deerfield Beach, Fla.). - 1998. - (2018) vom: 30. Mai, Seite e1707489 |
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| Weitere Verfasser: | , , , , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2018
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| Zugriff auf das übergeordnete Werk: | Advanced materials (Deerfield Beach, Fla.) |
| Schlagworte: | Journal Article Mott insulators X-ray absorption spectroscopy X-ray photoemission spectroscopy magnetic oxides |
| Zusammenfassung: | © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. When ferromagnetic films become ultrathin, key properties such as the Curie temperature and the saturation magnetization are usually depressed. This effect is thoroughly investigated in magnetic oxides such as half-metallic manganites, but much less in ferrimagnetic insulating perovskites such as rare-earth titanates RTiO3 , despite their appeal to design correlated 2D electron gases. Here, the magnetic properties of epitaxial DyTiO3 thin films are reported. While films thicker than about 50 nm show a bulk-like response, at low thickness a surprising increase of the saturation magnetization is observed. This behavior is described using a classical model of a "dead layer" but assuming that this layer is actually "living," that is, it responds to the magnetic field with a strong paramagnetic susceptibility. Through depth-dependent X-ray absorption and photoemission spectroscopy, it is shown that the "living-dead layer" corresponds to surface regions where magnetic (S = 1/2) Ti3+ ions are replaced by nonmagnetic Ti4+ ions. Hysteresis cycles at the Dy M 5 and Ti L 3 edges indicate that the surface Ti4+ ions decouple the Dy3+ ions, thus unleashing their strong paramagnetic response. Finally, it is shown how capping the DyTiO3 film can help increase the Ti3+ content near the surface and thus recover a better ferrimagnetic behavior |
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| Beschreibung: | Date Revised 27.02.2024 published: Print-Electronic ErratumIn: Adv Mater. 2018 Dec;30(51):e1805269. doi: 10.1002/adma.201805269. - PMID 30556635 Citation Status Publisher |
| ISSN: | 1521-4095 |
| DOI: | 10.1002/adma.201707489 |