Rise and fall of ferromagnetism in O-irradiated Al{sub 2}O{sub 3} single crystals

Journal Article · Sun Jun 21 00:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4922788· OSTI ID:22490708

Li, Qiang ^[1]; Xu, Juping; Liu, Jiandang; Du, Huaijiang; Ye, Bangjiao ^[1]

---

1. State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei 230026 (China)

In dilute magnetic semiconductors studies, sapphire was usually used as non-magnetic substrate for films. We observed weak ferromagnetic component in Al{sub 2}O{sub 3} single crystal substrate, and excluded the possibility of ferromagnetic contaminations carefully by inductively coupled plasma mass spectrometry and X-ray photoelectron spectroscopy. The ferromagnetism rise and fall during the process of annealing-oxygen irradiation-annealing of the sapphire. The ferromagnetic changes are consistent with Al-vacancy related defects detected by positron annihilation spectroscopy. With first-principle calculations, we confirm that Al-vacancy can introduce magnetic moment for 3 μB in Al{sub 2}O{sub 3} crystal and form stable V{sub Al}-V{sub Al} ferromagnetic coupling at room temperature.

• OSTI ID: 22490708
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 23; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALUMINIUM OXIDES
ANNEALING
ANNIHILATION
CONTAMINATION
COUPLING
DEFECTS
FERROMAGNETISM
FILMS
ICP MASS SPECTROSCOPY
IRRADIATION
MAGNETIC MOMENTS
MAGNETIC SEMICONDUCTORS
MONOCRYSTALS
OXYGEN
POSITRONS
SAPPHIRE
SUBSTRATES
TEMPERATURE RANGE 0273-0400 K
X-RAY PHOTOELECTRON SPECTROSCOPY