ZnO thin films made by sputtering: room temperature ferromagnetism due to Zn defects/vacancies?
Unlike TiO<sub>2</sub> and SnO<sub>2</sub>, room temperature ferromagnetism in pristine ZnO films does not appear to originate from oxygen vacancies. In this study, we investigated thin films of ZnO deposited on <i>R</i>-cut Al<sub>2</sub>O<sub>3</sub> by sputtering. The ZnO films were ferromagnetic, with a very high <i>T</i> <sub>C</sub> of about 800 K and were quite magnetically homogenous. Our experiments were complemented by quantum-mechanical calculations of both bulk wurtzite-structure ZnO and its (0001) surfaces, with and without Zn vacancies. While the bulk ground state and the bulk-terminated, vacancy-free (0001) surfaces were non-magnetic, a higher concentration of Zn vacancies deep beneath the surface was shown to contribute magnetic moments to the ferromagnetic state of ZnO.
Authors
- Ondřej Caha (ORCID: https://orcid.org/0000-0001-5626-031X)
- Satoshi Murakami (ORCID: https://orcid.org/0000-0001-5553-7663)
- Martin Friák (ORCID: https://orcid.org/0000-0003-1892-6859)
- Mojmír Meduňa (ORCID: https://orcid.org/0000-0001-9865-0500)
- Nguyen Sy Pham (ORCID: https://orcid.org/0000-0001-9105-4036)
- Ivana Miháliková (ORCID: https://orcid.org/0000-0002-2432-9930)
- Nguyen Hoa Hong (ORCID: https://orcid.org/0000-0003-0010-5710)
Institutions
- Japan Advanced Institute of Science and Technology (JP)
- Masaryk University (CZ)
- Czech Academy of Sciences, Institute of Physics of Materials (CZ)
Publication Details
- Journal
- RSC Advances
- Published
- 2025-01-01
- DOI
- https://doi.org/10.1039/d5ra00146c
- Citations
- 7
- Primary Topic
- ZnO doping and properties
- Type
- article
- Field-Weighted Citation Impact
- 3.62
Funders
- Japan Advanced Institute of Science and Technology
- Ministerstvo Školství, Mládeže a Tělovýchovy
- Grantová Agentura České Republiky
- Central European Institute of Technology
- National Supercomputing Center, Korea Institute of Science and Technology Information