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Title: Defect-induced ferromagnetism in undoped In{sub 2}O{sub 3} nanowires

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 largemore » surface area and intrinsic defects mediating the ferromagnetic ordering.« less
Authors:
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Publication Date:
OSTI Identifier:
22420711
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 60; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 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