Synthesis, microstructure, and electronic band structure properties of nanocrystalline neodymium-doped bismuth titanate ferroelectric films fabricated by the sol–gel method

Journal Article · Thu Jan 15 00:00:00 EST 2015 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2014.09.090· OSTI ID:22420763

Miao, Fengjuan ^[1]; Tao, Bairui ^[2]; Chu, Paul K. ^[3]

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1. College of Communications and Electronics Engineering, Qiqihar University, Heilongjiang 161006 (China)
2. National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China)
3. Department of Physics and Material Sciences, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

Graphical abstract: X-ray diffraction indicates that the films are polycrystalline with the pure perovskite phase. Ten Raman active modes and one silicon substrate mode can be observed. The A{sub 1} {sub g}[Bi] at about 59 cm{sup −1} is unchanged whereas the B{sub 1} {sub g} and A{sub 1} {sub g}[Ti] phonon modes shift towards higher frequencies. Photoluminescence shows that the intensities of the two peaks increase with Nd concentration except the Bi{sub 3}NdTi{sub 3}O{sub 12} film, due to the smallest grain size and oxygen vacancy defects. Good optical functions of the BNT films are achieved due to the SE suggesting potential applications in ferroelectric-based optoelectronic devices. - Abstract: Bi{sub 4−x}Nd{sub x}Ti{sub 3}O{sub 12} (BNT) films with different Nd contents (from 0 to 1 with 0.25 intervals) are prepared by the sol–gel process. The Nd substitution effects on the preferred orientation, surface morphology, phonon modes, emission bands, andelectronic band structures of the BNT films are investigated by microscopy, Raman scattering, photoluminescence, and spectroscopic ellipsometry (SE) at room temperature. X-ray diffraction indicates that the films are polycrystalline with the pure perovskite phase. Ten Raman active modes and one silicon substrate mode can be observed. The A{sub 1} {sub g}[Bi] at about 59 cm{sup −1} is unchanged whereas the B{sub 1} {sub g} and A{sub 1} {sub g}[Ti] phonon modes shift towards higher frequencies. Photoluminescence shows that the intensities of the two peaks increase with Nd concentration except the Bi{sub 3}NdTi{sub 3}O{sub 12} film, due to the smallest grain size and oxygen vacancy defects. Good optical functions of the BNT films are achieved due to the SE suggesting potential applications in ferroelectric-based optoelectronic devices.

• OSTI ID: 22420763
• Journal Information: Materials Research Bulletin, Vol. 61; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BISMUTH COMPOUNDS
CONCENTRATION RATIO
ELECTRICAL PROPERTIES
ELLIPSOMETRY
EMISSION SPECTROSCOPY
FERROELECTRIC MATERIALS
GRAIN ORIENTATION
GRAIN SIZE
NANOSTRUCTURES
NEODYMIUM COMPOUNDS
OPTOELECTRONIC DEVICES
PHONONS
PHOTOLUMINESCENCE
POLYCRYSTALS
RAMAN SPECTROSCOPY
THIN FILMS
TITANATES
VACANCIES
X-RAY DIFFRACTION