scholarly journals Preparation of SiO2-Capped Sr2MgSi2O7:Eu,Dy Nanoparticles with Laser Ablation in Liquid

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Mika Ishizaki ◽  
Takao Katagiri ◽  
Takao Sasagawa ◽  
Yoshitaka Kitamoto ◽  
Osamu Odawara ◽  
...  
Keyword(s):  
Optical Properties ◽  
Laser Ablation ◽  
Surface Defects ◽  
Water Molecules ◽  
Nonradiative Relaxation ◽  
Laser Ablation In Liquid ◽  
Stöber Method ◽  
Research Fields ◽  
Pl Intensity ◽  
The Stöber Method

The effect of SiO2capping on the optical properties of nanoparticles was investigated. The photoluminescence (PL) intensity was successfully improved by SiO2-capping. Sr2MgSi2O7:Eu,Dy nanoparticles were prepared by laser ablation in liquid. The SiO2capping was performed using the Stöber method with ultrasonication. The TEM images indicated that the Sr2MgSi2O7:Eu,Dy nanocrystal was capped with amorphous SiO2, and the shape of the completely capped nanoparticle was an elliptical nanorod, which aggregated after a long SiO2capping reaction time. The peak wavelength and the shape of the PL spectra were not changed by the pelletization and the laser ablation in liquid. The PL intensity of SiO2capped nanoparticles was significantly increased. Nonradiative relaxation via surface defects and energy transfer to water molecules decrease the PL intensity. These phenomena accelerate in the case of nanoparticles. SiO2capping would prevent these phenomena and improve the optical properties of nanoparticles. The combination of laser ablation in liquid and the chemical reaction is important to expand the applications of this method in various research fields.

scholarly journals Optical Properties of Afterglow Nanoparticles : , Capped with Polyethylene Glycol

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Fumitaka Yoshimura ◽  
Mika Ishizaki ◽  
Fumihiro Wakai ◽  
Masahiko Hara ◽  
Osamu Odawara ◽  
...  
Keyword(s):  
Optical Properties ◽  
Polyethylene Glycol ◽  
Laser Ablation ◽  
Quantum Yield ◽  
Surface Defects ◽  
Colloidal Solution ◽  
Decay Curve ◽  
Quantum Yields ◽  
Laser Ablation In Liquid ◽  
Initial Portion

The optical properties of afterglow nanoparticles were successfully improved by the addition of polyethylene glycol (PEG) to an afterglow colloidal solution. Afterglow nanoparticles—: , —were prepared by laser ablation in liquid. The quantum yields and the decay curves were measured by a fluorescence spectrophotometer. An increase in the amount of PEG added to the solution increased the quantum yield of the nanoparticles and improved the afterglow property in the initial portion of the decay curve. However, the afterglow property did not change after a substantial amount of time had passed. The afterglow nanoparticles were capped with PEG molecules, and surface defects of the nanoparticles were passivated, which decreased the optical properties.

Optical properties of MgO NPs produced by laser ablation in liquid

2021 ◽  
Author(s):  
Fattin A. Fadhil ◽  
Juhaina M. Taha ◽  
Khawla S. Khashan ◽  
Farah Mahdi
Keyword(s):  
Optical Properties ◽  
Laser Ablation ◽  
Laser Ablation In Liquid

Structural and optical properties of TiO2–Ge nanoparticles prepared through laser ablation in liquid medium

2017 ◽  
Vol 95 (7) ◽  
pp. 645-649 ◽  
Author(s):  
Shaista Shahzada ◽  
Anbarin Fatima ◽  
Asma Nazir ◽  
Arshad Mehmood ◽  
Mazhar Mehmood ◽  
...  
Keyword(s):  
Optical Properties ◽  
Laser Ablation ◽  
Average Particle Size ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Visible Range ◽  
Average Particle ◽  
Laser Ablation In Liquid ◽  
X Ray ◽  
Scanning Electron

Quantum dot (QD) composite nanoparticles of titania germanium (TiO2–Ge) were fabricated by pulsed laser ablation of composite targets of TiO2–Ge immersed in deionized water. The single phase crystallanity, lattice parameters, and the evaluation of crystallite size of nanoparticles was investigated by X-ray diffraction (XRD). The morphology of the samples was analyzed through scanning electron microscopic studies. The average particle size calculated through XRD and measured through scanning electron microscope is in the range from 18 to 29 nm and are in agreement with each other. Compositional study was carried out through electron dispersive X-ray analysis showing that the ablation rate of Ge is smaller than TiO2. Optical properties were measured by UV–visible transmission spectra and Raman spectroscopy. The band gap of composite particles varies from the UV to the visible range by varying concentration of Ge QDs. This work shows that pulsed laser ablation in liquid media is an easy approach to synthesize ultrafine, contamination-free nanosized material, which is difficult to produce by other conventional methods.

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