2D nature of magnetic states at SnO2 surfaces: a combined experimental and theoretical study
Authors | |
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Year of publication | 2024 |
Type | Article in Periodical |
Magazine / Source | RSC Advances |
MU Faculty or unit | |
Citation | |
Web | https://pubs.rsc.org/en/content/articlelanding/2024/ra/d4ra00734d |
Doi | http://dx.doi.org/10.1039/d4ra00734d |
Keywords | 2D; nanomaterials; ferromagnetism; magnetic semiconductors; defects |
Description | For undoped SnO2, room temperature ferromagnetism could be seen uniquely in 2-dimensional configurations, particularly in ultra-thin films (whose thickness is ideally below 100 nm). Both bulk samples and nano-powders of pristine SnO2 are diamagnetic, indicating that a 2D surface is a key point in shaping up the magnetic properties in SnO2. As a complement to our experiments, we have performed a series of quantum-mechanical calculations for the bulk rutile-structure SnO2 as well as its (001) and (101) surfaces. The calculations included several atomic configurations with and without vacancies in/under the studied surfaces. The stability of the non-magnetic ground state of rutile SnO2 bulk was cross-checked and confirmed by its phonon spectrum computed within the harmonic approximation. Regarding the surfaces, the bulk-like (001) surface containing Sn vacancies has turned out to be ferromagnetic, while the shift of Sn vacancies under the surface resulted in a more complex ferrimagnetic state. The bulk-like (001) surface without vacancies and that with the O vacancies are predicted to be non-magnetic. Regarding the (101) surfaces, those terminated by a single layer of oxygen atoms and those terminated by tin atoms are non-magnetic, while a surface terminated by two layers of oxygen has turned out to be ferromagnetic. |
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