STRUCTURAL AND OPTICAL PROPERTIES OF SINGLE CRYSTALLINE BISMUTH NANOPARTICLES IN POLYMER

2013 ◽  
Vol 22 ◽  
pp. 654-659 ◽  
Author(s):  
LUTFUL KABIR ◽  
SWAPAN K. MANDAL
Keyword(s):  
Optical Properties ◽  
Absorption Spectrum ◽  
Structural And Optical Properties ◽  
Chemical Route ◽  
Plasmon Band ◽  
Single Crystalline ◽  
Bismuth Nanoparticles ◽  
Transmission Electron ◽  
Average Size ◽  
Bi Nanoparticles

We report here the structural and optical properties of Bi nanoparticles in polymer (polypyrrole) matrix. The nanoparticles are synthesized following a wet chemical route. The X-ray diffraction data clearly shows the growth of single crystalline Bi nanoparticles within the host polymer. The microstructure of the Bi nanoparticles obtained by transmission electron microscopy (TEM) reveals clearly the formation of spherical shaped nanoparticles of average size∼27 nm with a narrow size distribution. The optical absorption spectrum exhibits a distinct peak at 278 nm which is attributed to the surface plasmon band of Bi nanoparticles. The absorption spectrum is found to be described well following Mie theory.

The effects of different polymerization agents on structural and optical properties of (K0.5Na0.5)NbO3 nanopowders synthesized by a facile green route

2014 ◽  
Vol 28 (28) ◽  
pp. 1450224 ◽  
Author(s):  
Gh. H. Khorrami ◽  
A. Kompany ◽  
A. Khorsand Zak
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Energy Band Gap ◽  
Structural And Optical Properties ◽  
Transmission Electron ◽  
Green Route ◽  
Xrd Patterns ◽  
Average Size

( K 0.5 N 0.5) NbO 3 lead-free nanopowders were synthesized by a modified sol–gel method in different media: gelatin, starch and chitosan, as polymerization and stabilizer agents. The proper temperature needed for calcinating the prepared gel was obtained using thermogravometric analysis (TGA). Structural and optical properties of the prepared powders were investigated and compared using X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-Vis diffused reflectance spectroscopy. The XRD patterns of the synthesized samples confirmed the formation of the orthorhombic structure at 600°C calcination temperature with no remarkable extra peaks. TEM images showed that the morphologies of the particles prepared in the three different media are cubic with the average size of about 69, 34 and 49 nm for gelatin, starch and chitosan, respectively. The value of the energy band gap of the samples was calculated by diffused reflectance spectroscopy, using Kubelka–Munk method. Our results showed that the type of the polymerization agent is important in preparing KNN nanoparticles and affects the structural and optical properties of the synthesized samples.

Structural and optical properties of KNN nanocubes synthesized by a green route using gelatin

2015 ◽  
Vol 08 (02) ◽  
pp. 1550030 ◽  
Author(s):  
Gh. H. Khorrami ◽  
A. Kompany ◽  
A. Khorsand Zak
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Structural Deformation ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Transmission Electron ◽  
Green Route ◽  
Vis Spectroscopy ◽  
Xrd Patterns ◽  
Average Size

Sodium potassium niobate nanoparticles [( K 0.5 Na 0.5) NbO 3, KNN ], KNN-NPs, were synthesized using a modified sol–gel method. Structural and optical properties of the prepared samples were investigated by thermogravometric analyzer (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman and UV–Vis spectroscopy. The XRD patterns showed that the formation of the orthorhombic KNN-NPs starts at 500°C calcination temperature. Raman spectroscopy was used to investigate the crystalline symmetry and the structural deformation of the prepared KNN-NPs. TEM images showed that the morphology of the prepared particles is cubic, with the average size of about 50 nm. From diffused reflectance spectroscopy along with using Kubelka–Munk method, the energy bandgaps were determined to be indirect with the values of 3.13 eV and 3.19 eV for the samples calcined at 500°C and 600°C, respectively.

Visualization of the Coalescence of Bismuth Nanoparticles

2014 ◽  
Vol 20 (2) ◽  
pp. 416-424 ◽  
Author(s):  
Kai-Yang Niu ◽  
Hong-Gang Liao ◽  
Haimei Zheng
Keyword(s):  
Precursor Solution ◽  
Growth Trajectories ◽  
Transport Mechanisms ◽  
Bismuth Nanoparticles ◽  
Transmission Electron ◽  
Liquid Cell ◽  
Significant Pathway ◽  
Mass Transport Mechanisms ◽  
Bi Nanoparticles

AbstractCoalescence is a significant pathway for the growth of nanostructures. Here we studied the coalescence of Bi nanoparticles in situ by liquid cell transmission electron microscopy (TEM). The growth of Bi nanoparticles was initiated from a bismuth neodecanoate precursor solution by electron beam irradiation inside a liquid cell under the TEM. A significant number of coalescence events occurred from the as-grown Bi nanodots. Both symmetric coalescence of two equal-sized nanoparticles and asymmetric coalescence of two or more unequal-sized nanoparticles were analyzed along their growth trajectories. Our observation suggests that two mass transport mechanisms, i.e., surface diffusion and grain boundary diffusion, are responsible for the shape evolution of nanoparticles after a coalescence event.

Thiol-Capped CdSe and CdTe Nanoclusters: Synthesis by a Wet Chemical Route, Structural and Optical Properties

1998 ◽  
Vol 536 ◽  
Author(s):  
A. L. Rogach ◽  
A Eychmüller ◽  
J. Rockenberger ◽  
A. Kornowski ◽  
H. Weller ◽  
...  
Keyword(s):  
Particle Size ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Chemical Route ◽  
X Ray ◽  
Stabilizing Agents ◽  
Transmission Electron ◽  
Wet Chemical ◽  
Wet Chemical Route ◽  
X Ray Absorption

AbstractCdSe and CdTe nanoclusters were formed in aqueous solutions at moderate temperatures by a wet chemical route in the presence of thiols as effective stabilizing agents. The nature of the stabilizing agent (thioalcohols or thioacids) had an important influence on the particle size and largely determined the photoluminescence properties. The nanoclusters were characterized by means of UV-vis absorption and photoluminescence spectroscopy, powder X-ray diffraction, high resolution transmission electron microscopy, and extended X-ray absorption fine structure measurements. CdSe and CdTe nanoclusters were crystalline, in the cubic zincblende phase, with mean sizes in the range of 2 to 5 nm depending on the preparative conditions and the postpreparative size-selective fractionation, and showed pronounced electronic transitions in the absorption spectra. Thioglycerol-stabilized CdTe nanoclusters possessed sharp band-egde photoluminescence being tunable with particle size.

CONTROLLED SYNTHESIS OF THE ZnWO4 NANOSTRUCTURE AND STUDY OF THEIR STRUCTURAL AND OPTICAL PROPERTIES

2012 ◽  
Vol 21 (01) ◽  
pp. 1250002 ◽  
Author(s):  
NGUYEN MANH HUNG ◽  
LAM THI HANG ◽  
NGUYEN VAN KHANH ◽  
DU THI XUAN THAO ◽  
NGUYEN VAN MINH
Keyword(s):  
Electron Microscopy ◽  
Grain Size ◽  
Optical Properties ◽  
Reaction Time ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Calcination Time ◽  
Transmission Electron ◽  
Pure Phase ◽  
Size And Morphology

We investigate the effects of calcination time and concentration of solution on the structure, as well as optical properties in ZnWO4 nanopowder prepared by hydrothermal method. The prepared powder were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman scattering, optical absorption and photoluminescent spectroscopy (PL). It is shown that the grain size and morphology of ZnWO4 nanopowder can be controlled by adjusting the reaction time as well as the concentration of the solution. The resultant sample is a pure phase of ZnWO4 without any impurities. The result showed that the optical property of ZnWO4 nanopowders depend on their grain size. The optical band gap becomes narrower as the reaction time or concentration of solution is increased. The improved PL properties of the ZnWO4 crystallites can be obtained with the optimal concentration of the solution.

scholarly journals Structural and Optical Properties of Self-Catalyzed Axially Heterostructured GaPN/GaP Nanowires Embedded into a Flexible Silicone Membrane

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2110
Author(s):  
Olga Yu. Koval ◽  
Vladimir V. Fedorov ◽  
Alexey D. Bolshakov ◽  
Sergey V. Fedina ◽  
Fedor M. Kochetkov ◽  
...  
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Molecular Beam ◽  
Nanowire Array ◽  
Growth Mechanisms ◽  
Structural And Optical Properties ◽  
Rubber Membrane ◽  
Transmission Electron ◽  
The Difference ◽  
Photoluminescence Studies

Controlled growth of heterostructured nanowires and mechanisms of their formation have been actively studied during the last decades due to perspectives of their implementation. Here, we report on the self-catalyzed growth of axially heterostructured GaPN/GaP nanowires on Si(111) by plasma-assisted molecular beam epitaxy. Nanowire composition and structural properties were examined by means of Raman microspectroscopy and transmission electron microscopy. To study the optical properties of the synthesized nanoheterostructures, the nanowire array was embedded into the silicone rubber membrane and further released from the growth substrate. The reported approach allows us to study the nanowire optical properties avoiding the response from the parasitically grown island layer. Photoluminescence and Raman studies reveal different nitrogen content in nanowires and parasitic island layer. The effect is discussed in terms of the difference in vapor solid and vapor liquid solid growth mechanisms. Photoluminescence studies at low temperature (5K) demonstrate the transition to the quasi-direct gap in the nanowires typical for diluted nitrides with low N-content. The bright room temperature photoluminescent response demonstrates the potential application of nanowire/polymer matrix in flexible optoelectronic devices.

Change in yhe Optical Properties of Sapphire Induced by Ion Implantation

1997 ◽  
Vol 504 ◽  
Author(s):  
D. Ila ◽  
E. K. Williams ◽  
S. Sarkisov ◽  
D. B. Poker ◽  
D. K. Hensley
Keyword(s):  
Optical Properties ◽  
Optical Absorption ◽  
Full Width Half Maximum ◽  
Rutherford Backscattering Spectrometry ◽  
Full Width ◽  
Half Maximum ◽  
Transmission Electron ◽  
Before And After ◽  
Linear Optical Properties ◽  
Average Size

ABSTRACTWe have studied the formation of nano-crystals, after implantation of 2.0 MeV gold, 1.5 MeV silver, 160 keV copper and 160 keV tin into single crystal of A12O3. We also studied the change in the linear optical properties of the implanted Al2O3 before and after subsequent annealing by measuring the increase in resonance optical absorption. Applying Doyle's theory and the results obtained from Rutherford backscattering spectrometry (RBS) as well as the full width half maximum of the absorption band from Optical Absorption Photospectrometry (OAP), we measured the average size of the metallic clusters for each sample after heat treatment. The formation and crystallinity of the nanoclusters were also confirmed using transmission electron microscopy (TEM) technique.

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