2016 Fiscal Year Annual Research Report
New fabrication of (Y,Gd)2O3:Tb3+ transparent ceramics using ultrafine monospheres
| Project/Area Number |
26420686
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| Research Institution | National Institute for Materials Science |
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Principal Investigator |
李 継光 国立研究開発法人物質・材料研究機構, 機能性材料研究拠点, 主幹研究員 (90354381)
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Keywords | 透明セラミックス材料 / 球形微粒子 / 焼結 / 光物性 |
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| Outline of Annual Research Achievements |
(Y0.95-xGdxTb0.05)(OH)CO3.H2O monosheres with the average diameter well controlled in the wide range of 110-590 nm were successfully synthesized via homogeneous precipitation. The nucleation density of precipitation and therefore the average size can be adjusted by the concentration of the urea precipitant and ammonium nitrate mineralizer. (Y0.95-xGdxTb0.05)2O3 ceramics with in-line transmittances reaching 80% were then fabricated via vaccum sintering at 1700 deg C for 4 h of the well-dispersed oxide particles calcined from such basic-carbonate monosheres. Colloidal processing was found to be advantageous over CIP for forming, since it produces dense green bodies of high microstructure uniformity. Localized domains were observed in the green body made via CIP, which sinter in priority than the surrounding matrix and thus produce micro-cracks harmful to the fabrication of transparent ceramics. The optimal Gd content was determined to be 2 at% for the 545 nm green-emission of Tb3+. Besides, with the (Y1-xGdxTb0.05)2(OH)5NO3.nH2O nanosheets as a new type of precursor for well-sinterable oxide powders, single-crystal like transparent ceramics (transmittance: 80-83%) were also fabricated via vacuum sintering at 1700 degC for 4 h. It was found that a lower heating rate of vacuum sintering allows uniform densification of the green body from the surface to interior, and thus produces ceramics of higher transparency. The emission of Tb3+ improves with increasing crystallite/particle size of the powder and ceramic, and has the fluorescence lifetime of about 1.5-2.8 ms.
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[Journal Article] Hydrothermal crystallization of a Ln2(OH)4SO4.nH2O layered compound for a wide range of Ln (Ln=La-Dy), thermolysis, and facile transformation into oxysulfate and oxysulfide phosphors2017
Author(s)
X.J. Wang, J.-G. Li, M.S. Molokeev, X.J. Wang, W.G. Liu, Q. Zhu, H. Tanaka, K. Suzuta, B.-N. Kim, Y. Sakka
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Journal Title
RSC Advances
Volume: 7
Pages: 13331～13339
DOI
Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
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[Journal Article] Sulfate exchange of the nitrate-type layered hydroxide nanosheets of Ln2(OH)5NO3.nH2O for better dispersed and multi-color luminescent Ln2O3 nanophosphors (Ln=Y0.98RE0.02, RE=Pr, Sm, Eu, Tb, Dy, Ho, Er, and Tm)2016
Author(s)
X.L. Wu, W.G. Liu, J.-G. Li, Q. Zhu, X.D. Li, X.D. Sun
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Journal Title
Nanoscale Research Letters
Volume: 11(328)
Pages: －
DOI
Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
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[Journal Article] Layered hydroxyl sulfate: Controlled crystallization, structure analysis, and green derivation of multi-color luminescent (La,RE)2O2SO4 and (La,RE)2O2S phosphors (RE=Pr, Sm, Eu, Tb, and Dy)2016
Author(s)
X.J. Wang, J.-G. Li, M.S. Molokeev, Q. Zhu, X.D. Li, X.D. Sun
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Journal Title
Chemical Engineering Journal
Volume: 302
Pages: 577～586
DOI
Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
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