Entity

Time filter

Source Type


Zhu K.,Nanjing University of Technology | Ding W.,Institute 53 of Chinas Ordnance Industry | Sun W.,Nanjing University of Technology | Han P.,Yancheng Institute of Technology | And 2 more authors.
Journal of Materials Science: Materials in Electronics | Year: 2016

Laser stealth absorption material Sm2O2S was successfully synthesized by a solid state flux fusion method. The phase composition, morphology and optical property were investigated by X-ray diffraction with Rietveld structure refinement, scanning electron microscopy, thermogravimetry–differential scanning calorimetry and ultraviolet–visible spectrophotometer. The results showed that Li2CO3/Na2CO3 composites were the optimal flux for the crystal formation. Na2CO3 plays an important role during the reaction. With the increase of temperature, crystal structure became regular. The hexagonal shape powders could be achieved above 1100 °C. Furthermore, the as-prepared Sm2O2S powder had an intense absorption around 1.06 μm, causing by electron transitions from ground state 6H5/2 to excited state 6F9/2. The study indicated that Sm2O2S can be a promising 1.06 μm laser absorption material. © 2015, Springer Science+Business Media New York. Source


Sun W.,Nanjing University of Technology | Sun W.,Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites | Xu H.,Nanjing University of Technology | Xu H.,Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites | And 7 more authors.
Journal of Materials Science: Materials in Electronics | Year: 2016

A novel 1.54 μm laser absorbent of Er2O2S was prepared by solid state flux method. The effects of different calcining temperatures and preservation time on the synthesis and reflecting property of Er2O2S were investigated. The mechanism of fluxing agent was assumed and proved. The phase composition, morphology, and reflectivity of the powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet visible spectrophotometer (UV-3600PC). The results showed that pure phase of Er2O2S could be obtained with Na2CO3 as fluxing agent at 800–1200 °C, too high temperature and too long preservation time were bad for synthesizing Er2O2S. Na2CO3 played an important role during the reaction, the elemental sulfur in Er2O2S came from Na2S2O3 indeed. Different calcination conditions had a great impact on particle morphology, which had influence on the reflectivity of the products. The reflectivity was the lowest (0.39 %) when the calcining temperature was 1200 °C. © 2016 Springer Science+Business Media New York Source


Liu Q.,Nanjing University of Technology | Wang L.,Nanjing University of Technology | Zhang L.,Jiangsu University | Yang H.,Jiangsu University | And 2 more authors.
Journal of Materials Science: Materials in Electronics | Year: 2015

Double perovskite KLaMgWO6:Eu3+ phosphors were successfully synthesized by an improved sol–gel method using citric acid and polyethylene glycol as complexing agents. The structure evolution and photoluminescence were systematically invested by X-ray diffraction, Rietveld refinement and fluorescence spectra. The structure of Eu3+ doped samples was double-perovskite with space group C2/m. Enhanced luminescence properties were gotten by adding 5.0 wt% PEG. Na+ with smaller radius was selected to substitute K+ in this novel host. With increasing the concentration of Na+, the tolerance factors decreased and the structure of BO6 tilted gradually and lowered structure symmetry. Then the emission intensity ratio of 5D0–7F2/5D0–7F1 transition increased and the red emission played the dominate role. Also the emission intensity was enhanced by increasing the concentration of Na+. The phosphors showed better color purity with better CIE chromaticity coordinates. Therefore the synthesized phosphors is a potential light conversion red material for light emitting diode. © 2015, Springer Science+Business Media New York. Source


Yang W.,Nanjing University of Technology | Zhang B.,Nanjing University of Technology | Ding N.,Nanjing University of Technology | Ding W.,Nanjing University of Technology | And 4 more authors.
Ultrasonics Sonochemistry | Year: 2016

Green emission ZnO quantum dots were synthesized by an ultrasonic sol-gel method. The ZnO quantum dots were synthesized in various ultrasonic temperature and time. Photoluminescence properties of these ZnO quantum dots were measured. Time-resolved photoluminescence decay spectra were also taken to discover the change of defects amount during the reaction. Both ultrasonic temperature and time could affect the type and amount of defects in ZnO quantum dots. Total defects of ZnO quantum dots decreased with the increasing of ultrasonic temperature and time. The dangling bonds defects disappeared faster than the optical defects. Types of optical defects first changed from oxygen interstitial defects to oxygen vacancy and zinc interstitial defects. Then transformed back to oxygen interstitial defects again. The sizes of ZnO quantum dots would be controlled by both ultrasonic temperature and time as well. That is, with the increasing of ultrasonic temperature and time, the sizes of ZnO quantum dots first decreased then increased. Moreover, concentrated raw materials solution brought larger sizes and more optical defects of ZnO quantum dots. © 2015 Elsevier B.V. Source


Yang W.,Nanjing University of Technology | Yang H.,Nanjing University of Technology | Ding W.,Nanjing University of Technology | Ding W.,Institute 53 of Chinas Ordnance Industry | And 5 more authors.
Ultrasonics Sonochemistry | Year: 2016

Green emission ZnO quantum dots were synthesized by an ultrasonic microreactor. Ultrasonic radiation brought bubbles through ultrasonic cavitation. These bubbles built microreactor inside the microreactor. The photoluminescence properties of ZnO quantum dots synthesized with different flow rate, ultrasonic power and temperature were discussed. Flow rate, ultrasonic power and temperature would influence the type and quantity of defects in ZnO quantum dots. The sizes of ZnO quantum dots would be controlled by those conditions as well. Flow rate affected the reaction time. With the increasing of flow rate, the sizes of ZnO quantum dots decreased and the quantum yields first increased then decreased. Ultrasonic power changed the ultrasonic cavitation intensity, which affected the reaction energy and the separation of the solution. With the increasing of ultrasonic power, sizes of ZnO quantum dots first decreased then increased, while the quantum yields kept increasing. The effect of ultrasonic temperature on the photoluminescence properties of ZnO quantum dots was influenced by the flow rate. Different flow rate related to opposite changing trend. Moreover, the quantum yields of ZnO QDs synthesized by ultrasonic microreactor could reach 64.7%, which is higher than those synthesized only under ultrasonic radiation or only by microreactor. © 2016 Elsevier B.V. Source

Discover hidden collaborations