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Author Tien, Li-Chia ♦ Hsieh, Yu-Yun
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ NANOSCIENCE AND NANOTECHNOLOGY ♦ EVAPORATION ♦ FERROMAGNETISM ♦ FIELD EMISSION ♦ INDIUM OXIDES ♦ MONOCRYSTALS ♦ NANOWIRES ♦ OPTICAL PROPERTIES ♦ PHOTOLUMINESCENCE ♦ SCANNING ELECTRON MICROSCOPY ♦ SQUID DEVICES ♦ TEMPERATURE DEPENDENCE ♦ TEMPERATURE RANGE 0273-0400 K ♦ TRANSMISSION ELECTRON MICROSCOPY ♦ ULTRAVIOLET RADIATION ♦ VACANCIES ♦ X-RAY DIFFRACTION ♦ X-RAY PHOTOELECTRON SPECTROSCOPY
Abstract Highlights: • Undoped In{sub 2}O{sub 3} nanowires were synthesized by a thermal evaporation method. • In{sub 2}O{sub 3} nanowires show d{sup 0} ferromagnetism at room temperature. • Large amount of defects were confirmed by PL, UV/vis, and XPS. • Oxygen deficient surfaces and size effect mediating ferromagnetic ordering. - Abstract: We report the observation of intrinsic room-temperature ferromagnetism in undoped In{sub 2}O{sub 3} nanowires synthesized by a thermal evaporation method. The as-grown sample was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), temperature-dependent photoluminescence (PL), Ultraviolet–visible spectroscopy (UV/vis), X-ray photoelectron spectroscopy (XPS), and superconducting quantum interference device (SQUID). Structural characterizations show that the as-grown sample is single crystal cubic bixbyite structure with 80–100 nm in diameter and 2–4 μm long. Both PL and UV/vis results reveal that the sample exhibits large amount of oxygen vacancies and indium vacancies (V{sub O} and V{sub In}). XPS results indicate that the In{sub 2}O{sub 3} nanowires are significantly oxygen deficient and non-stoichiometric at surface. Experimentally measured magnetic hysteresis curves for undoped In{sub 2}O{sub 3} nanowires clearly display ferromagnetic behavior at room temperature. We believe the ferromagnetism of undoped In{sub 2}O{sub 3} nanowires is ascribed to the large surface area and intrinsic defects mediating the ferromagnetic ordering.
ISSN 00255408
Educational Use Research
Learning Resource Type Article
Publisher Date 2014-12-15
Publisher Place United States
Journal Materials Research Bulletin
Volume Number 60


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