EDTA-assisted phase conversion synthesis of (Gd0.95RE0.05)PO4 nanowires (RE = Eu, Tb) and investigation of photoluminescence
Autor: | Zhengrong Ai, Yoshio Sakka, Ji-Guang Li, Byung-Nam Kim, Zhihao Wang, Xudong Sun, Zhu Qi, Xiaodong Li |
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Jazyk: | angličtina |
Rok vydání: | 2017 |
Předmět: |
Materials science
Photoluminescence lcsh:Biotechnology Analytical chemistry Nanowire 02 engineering and technology GdPO4 010402 general chemistry 01 natural sciences Article law.invention Magazine Phase conversion law lcsh:TP248.13-248.65 lcsh:TA401-492 General Materials Science 105 Low-Dimension (1D/2D) materials Hexagonal crystal system EDTA Optical Magnetic and Electronic Device Materials 505 Optical / Molecular spectroscopy 40 Optical magnetic and electronic device materials 021001 nanoscience & nanotechnology 0104 chemical sciences nanowires photoluminescence lcsh:Materials of engineering and construction. Mechanics of materials 0210 nano-technology Nuclear chemistry |
Zdroj: | Science and Technology of Advanced Materials, Vol 18, Iss 1, Pp 447-457 (2017) Science and Technology of Advanced Materials |
ISSN: | 1878-5514 1468-6996 |
Popis: | Hexagonal (Gd0.95RE0.05)PO4·nH2O nanowires ~300 nm in length and ~10 nm in diameter have been converted from (Gd0.95RE0.05)2(OH)5NO3·nH2O nanosheets (RE = Eu, Tb) in the presence of monoammonium phosphate (NH4H2PO4) and ethylene diamine tetraacetic acid (EDTA). They were characterized by X-ray diffraction, thermogravimetry, electron microscopy, and Fourier transform infrared and photoluminescence spectroscopies. It is shown that EDTA played an essential role in the morphology development of the nanowires. The hydrothermal products obtained up to 180 °C are of a pure hexagonal phase, while monoclinic phosphate evolved as an impurity at 200 °C. The nanowires undergo hexagonal→monoclinic phase transformation upon calcination at ≥600 °C to yield a pure monoclinic phase at ~900 °C. The effects of calcination on morphology, excitation/emission, and fluorescence decay kinetics were investigated in detail with (Gd0.95Eu0.05)PO4 as example. The abnormally strong 5D0→7F4 electric dipole Eu3+ emission in the hexagonal phosphates was ascribed to site distortion. The process of energy migration was also discussed for the optically active Gd3+ and Eu3+/Tb3+ ions. |
Databáze: | OpenAIRE |
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