Eu3+/Tb3+ Co-Doped Cerium Oxide Transparent Nanocomposite for Color-Tunable Emission

NANO ◽  
2018 ◽  
Vol 13 (10) ◽  
pp. 1850119
Author(s):  
Xiaoyan Li ◽  
Yunlong Yu ◽  
Xiangfeng Guan ◽  
Peihui Luo ◽  
Linqin Jiang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Transmission Electron Microscopy ◽  
Sol Gel ◽  
Homogeneous Precipitation ◽  
Transmission Electron ◽  
Color Tunable ◽  
Co Doped ◽  
Tunable Emission

Eu[Formula: see text]/Tb[Formula: see text] co-doped nanocomposite containing CeO2 nanocrystals was successfully prepared by an in situ sol–gel polymerization approach. High-resolution transmission electron microscopy demonstrated the homogeneous precipitation of CeO2 nanocrystals among the polymethylmethacrylate (PMMA) matrix. The thermal stability and UV-shielding capability of the obtained nanocomposite were improved with increase of CeO2 content. The tuning of the emissive color from green and yellow to red can be easily achieved by varying the dopant species and concentration. These results suggested that the obtained nanocomposite could be potentially applicable in transparent solid-state luminescent devices.

Thermal stability of laser-induced modified volumes in Si as studied by in situ and ex situ heating experiments

Microscopy ◽  
2018 ◽  
Vol 67 (2) ◽  
pp. 112-120
Author(s):  
Hiroyasu Saka ◽  
Hiroyuki Iwata ◽  
Daisuke Kawaguchi
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Transmission Electron Microscopy ◽  
Laser Beam ◽  
Ex Situ ◽  
Dislocation Theory ◽  
Tail Region ◽  
Transmission Electron ◽  
Thermal Stability Of

Abstract Radiation of a permeable laser beam into Si induces considerable modification of structures. Thermal stability of the laser-induced modified volumes (LIMV’s) was studied comprehensively by means of in situ and ex situ heating experiments using transmission electron microscopy. The behavior in the tail region of a LIMV can be understood by dislocation theory, while that of a void formed at the very focus of a laser beam cannot be understood easily.

scholarly journals Thermal stability of CsPbBr3 perovskite as revealed by in situ transmission electron microscopy

APL Materials ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 071110 ◽  
Author(s):  
Chao Zhang ◽  
Joseph F. S. Fernando ◽  
Konstantin L. Firestein ◽  
Joel E. von Treifeldt ◽  
Dumindu Siriwardena ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Transmission Electron Microscopy ◽  
Transmission Electron ◽  
Thermal Stability Of

scholarly journals Reversible Redox Property of Co(III) in Amorphous Co-doped SiO2/γ-Al2O3 Layered Composites

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5345
Author(s):  
Shotaro Tada ◽  
Shota Saito ◽  
Akito Mori ◽  
Hideki Mizuno ◽  
Shiori Ando ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Redox Reactions ◽  
Composite Powder ◽  
Amorphous Sio2 ◽  
X Ray ◽  
Transmission Electron ◽  
Reversible Redox ◽  
Co Doped

This paper reports on a unique reversible reducing and oxidizing (redox) property of Co(III) in Co-doped amorphous SiO2/γ-Al2O3 composites. The Fenton reaction during the H2O2-catalyzed sol–gel synthesis utilized in this study lead to the partial formation of Co(III) in addition to Co(II) within the composites. High-resolution transmission electron microscopy (HRTEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) analyses for the composite powder sample with a composition of Al:Si:Co = 85:10:5 showed the amorphous state of the Co-doped SiO2 that modified γ-Al2O3 nanocrystalline surfaces. In situ X-ray absorption fine structure (XAFS) spectroscopic analysis suggested reversible redox reactions of Co species in the composite powder sample during heat-treatment under H2 at 500 °C followed by subsequent cooling to RT under Ar. Further analyses by in situ IR spectroscopy combined with cyclic temperature programmed reduction/desorption (TPR/TPD) measurements and X-ray photoelectron spectroscopic (XPS) analysis revealed that the alternating Co(III)/(II) redox reactions were associated with OH formation (hydrogenation)-deformation (dehydrogenation) of the amorphous aluminosilicate matrix formed in situ at the SiO2/γ-Al2O3 hetero interface, and the redox reactions were governed by the H2 partial pressure at 250–500 °C. As a result, a supported mesoporous γ-Al2O3/Co-doped amorphous SiO2/mesoporous γ-Al2O3 three-layered composite membrane exhibited an H2-triggered chemical valve property: mesopores under H2 flow (open) and micropores under He flow (closure) at 300–500 °C.

Thermal Stability of Atomic Layer Deposited Zr:Al Mixed Oxide Thin Films: An in Situ Transmission Electron Microscopy Study

2005 ◽  
Vol 20 (7) ◽  
pp. 1741-1750
Author(s):  
L.C. Nistor ◽  
O. Richard ◽  
C. Zhao ◽  
H. Bender ◽  
G. Van Tendeloo
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Thermal Stability ◽  
Transmission Electron Microscopy ◽  
Atomic Layer ◽  
Silicon Surfaces ◽  
Transmission Electron ◽  
Thermal Stability Of

The thermal stability of amorphous Zr:Al mixed oxide films of different composition, produced on (001) silicon wafers by the atomic layer deposition method is studied by transmission electron microscopy during in situ heating experiments. The temperatures at which phase separation and crystallization occur are composition dependent. The crystallization of thick films (55–70 nm), deposited on HF-treated silicon surfaces covered with a 15 cycles Al2O3 layer, results in the formation of cubic ZrO2 and cubic γ–Al2O3. In very thin films (5 nm), deposited on silicon surfaces covered with a 0.5 nm SiO2 thin film, the formation of tetragonal zirconium disilicide (ZrSi2) is observed in the microscope vacuum, at temperatures above 900 °C. This effect depends on the thickness of the as deposited thin film.

Sign in / Sign up

Export Citation Format

Share Document