Aeschlimann, Raphael and Preziosi, Daniele and Scheiderer, Philipp and Sing, Michael and Valencia, Sergio and Santamaria, Jacobo and Luo, Chen and Ryll, Hanjo and Radu, Florin and Claessen, Ralph and Piamonteze, Cinthia and Bibes, Manuel (2018) A Living-Dead Magnetic Layer at the Surface of Ferrimagnetic DyTiO3 Thin Films. ADVANCED MATERIALS, 30 (29): 1707489. ISSN 0935-9648, 1521-4095
Full text not available from this repository. (Request a copy)Abstract
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.
Item Type: | Article |
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Uncontrolled Keywords: | X-RAY-ABSORPTION; OXIDES; RTIO3; magnetic oxides; Mott insulators; X-ray absorption spectroscopy; X-ray photoemission spectroscopy |
Subjects: | 500 Science > 530 Physics |
Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Back > Group Christian Back |
Depositing User: | Dr. Gernot Deinzer |
Date Deposited: | 06 Mar 2020 12:53 |
Last Modified: | 06 Mar 2020 12:54 |
URI: | https://pred.uni-regensburg.de/id/eprint/14222 |
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