scholarly journals Spectral and luminescent properties of ZnO–SiO2 core–shell nanoparticles with size-selected ZnO cores

RSC Advances ◽  
2014 ◽  
Vol 4 (108) ◽  
pp. 63393-63401 ◽  
Author(s):  
A. E. Raevskaya ◽  
Ya. V. Panasiuk ◽  
O. L. Stroyuk ◽  
S. Ya. Kuchmiy ◽  
V. M. Dzhagan ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Luminescent Properties ◽  
Nanoparticle Size ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Spectral And Luminescent Properties ◽  
Core Shell Nanoparticles

Deposition of a SiO2 shell on luminescent ZnO nanoparticles in dimethylsulfoxide precisely tunes the nanoparticle size from 3 to 6 nm.

Preparation and Luminescent Properties of Core-shell Nanoparticles Gd2O3∶Tb3+/SiOx

2013 ◽  
Vol 34 (5) ◽  
pp. 554-558 ◽  
Author(s):  
欧梅桂 OU Mei-gui ◽  
蔡少韩 CAI Shao-han ◽  
杨春林 YANG Chun-lin ◽  
Pascal Perriat Pascal Perriat
Keyword(s):  
Luminescent Properties ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

scholarly journals Synthesis of Core/Shell CuO-Zno Nanoparticles and Their Second-Harmonic Generation Performance / Kodols/Čaula Cuo-Zno Nanodaļiņu Sintēze Un To Spēja Ģenerēt Otrās Harmonikas Signālu

2015 ◽  
Vol 52 (5) ◽  
pp. 41-46 ◽  
Author(s):  
E. Tamanis ◽  
E. Sledevskis ◽  
A. Ogurcovs ◽  
V. Gerbreders ◽  
V. Paskevics
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Zno Nanoparticles ◽  
Atomic Oxygen ◽  
Second Harmonic ◽  
Exciting Radiation ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Harmonic Intensity ◽  
Core Shell Nanoparticles

Abstract The present paper presents the method for obtaining core/shell CuO-ZnO nanoparticles and nanocoatings by using a commercially available vacuum coating system. Initially generated Cu-Zn core/shell nanoparticles have been oxidised with a highly reactive atomic oxygen beam. Second-harmonic generation has been observed in the obtained samples. The dependence of second- harmonic intensity on the wavelength of the exciting radiation is shown in the paper.

scholarly journals Hydrothermal diffusion of Eu3+ in EuVO4@YVO4 core-shell nanoparticles and its influence on luminescent properties

2014 ◽  
Vol 63 (14) ◽  
pp. 147801
Author(s):  
Xie Di-Ni ◽  
Peng Hong-Shang ◽  
Huang Shi-Hua ◽  
You Fang-Tian ◽  
Wang Xiao-Hui
Keyword(s):  
Luminescent Properties ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

Luminescent properties of Nd3+-doped LaF3 core/shell nanoparticles with enhanced near infrared (NIR) emission

2010 ◽  
Vol 494 (1-3) ◽  
pp. 60-63 ◽  
Author(s):  
Xiaoxia Cui ◽  
Jiangbo She ◽  
Chao Gao ◽  
Kai Cui ◽  
Chaoqi Hou ◽  
...  
Keyword(s):  
Near Infrared ◽  
Luminescent Properties ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Nir Emission ◽  
Core Shell Nanoparticles

scholarly journals NIR-II Upconversion Photoluminescence of Er3+ Doped LiYF4 and NaY(Gd)F4 Core-Shell Nanoparticles

2021 ◽  
Vol 9 ◽  
Author(s):  
Qilong Feng ◽  
Wenjing Zheng ◽  
Jie Pu ◽  
Qiaoli Chen ◽  
Wei Shao
Keyword(s):  
Near Infrared ◽  
High Efficiency ◽  
Protective Layer ◽  
Luminescent Properties ◽  
Core Shell ◽  
Potential Candidate ◽  
Shell Nanoparticles ◽  
Surface Luminescence ◽  
The Difference ◽  
Core Shell Nanoparticles

The availability of colloidal nano-materials with high efficiency, stability, and non-toxicity in the near infrared-II range is beneficial for biological diagnosis and therapy. Rare earth doped nanoparticles are ideal luminescent agents for bio-applications in the near infrared-II range due to the abundant energy level distribution. Among them, both excitation and emission range of Er3+ ions can be tuned into second biological window range. Herein, we report the synthesis of ∼15 nm LiYF4, NaYF4, and NaGdF4 nanoparticles doped with Er3+ ions and their core-shell structures. The luminescent properties are compared, showing that Er3+ ions with single-doped LiYF4 and NaYF4 nanoparticles generate stronger luminescence than Er3+ ions with doped NaGdF4, despite the difference in relative intensity at different regions. By epitaxial growth an inert homogeneous protective layer, the surface luminescence of the core-shell structure is further enhanced by about 5.1 times, 6.5 times, and 167.7 times for LiYF4, NaYF4, and NaGdF4, respectively. The excellent luminescence in both visible and NIR range of these core-shell nanoparticles makes them potential candidate for bio-applications.

scholarly journals Solution-Phase Synthesis of Nanoparticles and Growth Study

2021 ◽  
Author(s):  
◽  
Soshan Cheong
Keyword(s):  
Iron Carbide ◽  
Precursor Concentration ◽  
Nanoparticle Size ◽  
Core Shell ◽  
High Concentration ◽  
Shell Nanoparticles ◽  
Synthesis Of Nanoparticles ◽  
Solution Phase Synthesis ◽  
Core Shell Nanoparticles

<p>This thesis is concerned with solution-phase synthesis of nanoparticles and growth of nanoparticles in solution. A facile synthesis route was developed to produce nanoparticles of iron, iron carbide and ruthenium. In general, the synthesis involved the reaction/decomposition of a metal precursor in solution, in the presence of a stabilising agent, in a closed reaction vessel, under a hydrogen atmosphere. The crystallinity, crystal structure, morphology and chemical composition of the nanoparticles obtained were studied primarily by transmission electron microscopy (TEM), selected area electron diffraction (SAED), powder X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDS). Scanning quantum interference device magnetometry (SQUID) was used to characterise the magnetic properties of iron and iron carbide nanoparticles. In situ synchrotron-based XRD was employed to investigate the growth of platinum nanoparticles of different morphologies.  The synthesis of iron and iron carbide nanoparticles was investigated at temperatures 80-160 °C. Syntheses at 130 °C and above produced mainly single-crystal α-Fe nanoparticles, whereas those at lower temperatures yielded products consisting of α-Fe and Fe₃C nanoparticles. Nanoparticles of larger than 10 nm oxidised on the surface leading to core/shell structures, and those of smaller size oxidised completely upon exposure to air. Core/shell nanoparticles of larger than 15 nm were observed to be stable under ambient conditions for at least a year, whereas those smaller in size underwent further oxidation forming core/void/shell structures. The magnetic properties of selected samples were characterised. The core/shell nanoparticles were shown to exhibit ferromagnetic behaviours, and saturation magnetisations were obtained at the range of 100-130 emu g⁻¹.  Nanoparticle size and size distribution, and morphology were found to be a result of combined effect of precursor concentration and the relative stabiliser concentration. In general, high-precursor concentration resulted in less controlled reaction and produced large nanoparticle size and size distribution. Under the high-concentration condition, the use of stabilisers in reduced amount then led to a diverse range of morphologies, which include dimer, porous and branched structures.  As for the synthesis of ruthenium nanoparticles, reactions of different precursors were investigated at temperatures ranging from room temperature to 140 °C. Highly crystalline ruthenium nanoparticles of different sizes and morphologies were obtained through different experimental conditions. The increase in nanoparticle size was found to be a result of increasing reaction temperature and/or decreasing stabiliser to ruthenium ratio. This trend was observed to be independent of the type of stabilisers and precursors used. The use of stabilisers with different binding characteristics has facilitated the formation of non-spherical nanoparticles; these include rod-like structures with high aspect ratios (of up to 12), hexagonal and truncated triangular plate-like structures, and tripods.  The growth of faceted and branched structures of platinum nanoparticles was investigated by employing in situ XRD techniques. TEM was used to examine the intermediate structures. The two different morphologies were previously shown to be governed by precursor concentration. It was found that the growth in the low-concentration reaction was characteristic of a thermodynamically controlled regime, whereas that in the high-concentration reaction occurred at much greater rates under a kinetically controlled regime. Based on the observations obtained, different growth mechanisms were proposed and discussed. The former involved an oriented attachment mechanism, while the latter, a novel mechanism involving selective growth and etching processes.  The results are followed by an overall discussion comparing and contrasting the various syntheses involved, and relating the results of syntheses to those of the growth studies.</p>

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