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.

Formation of Nanocluster Colloids of Tin, Gold and Copper in Magnesium Oxide by MeV Ion Implantation

1997 ◽  
Vol 504 ◽  
Author(s):  
R. L. Zimmerman ◽  
D. Ila ◽  
E. K. Williams ◽  
S. Sarkisov ◽  
D. B. Poker ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Single Crystals ◽  
Magnesium Oxide ◽  
Room Temperature ◽  
Full Width Half Maximum ◽  
Rutherford Backscattering Spectrometry ◽  
Threshold Fluence ◽  
Full Width ◽  
Half Maximum ◽  
Absorption Bands

ABSTRACTWe have implanted ions of Sn, Au and Cu at energies between 160 keV and 2.0 MeV into single crystals of MgO (100) at room temperature. The formation of nanoclusters was confirmed using photospectrometry, in combination with Mie's theory, which was indirect but nondestructive. Using Doyle's theory, as well as Rutherford Backscattering Spectrometry (RBS), we correlated the full width half maximum of the absorption bands to the estimated size of the metallic nanoclusters between 1–10 nm. These clusters were formed both by over implantation and by a combination of threshold fluence of the implanted species and post thermal annealing. The changes in the estimated size of the nanoclusters, after annealing at temperatures ranging from 500°C to 1000°C, were observed using photospectrometry.

The Optical Properties of ION Implanted Silica

1997 ◽  
Vol 504 ◽  
Author(s):  
C. C. Smith ◽  
D. Ila ◽  
E. K. Williams ◽  
D. B. Poker ◽  
D. K. Hensley
Keyword(s):  
Optical Properties ◽  
Absorption Band ◽  
Optical Absorption ◽  
Electron Microscopic ◽  
Absorption Bands ◽  
Optical Absorption Band ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Before And After ◽  
Microscopic Techniques

ABSTRACTWe present the results of our investigation of the change in the optical properties of silica, "suprasil", after keV through MeV implantation of copper, tin, silver and gold and after annealing. Suprasil, name brand of silica glass produced by Hereaus Amersil, which is chemically highly pure with well known optical properties. Both linear and nonlinear optical properties of the implanted silica were investigated before and after thermal annealing. All implants showed strong optical absorption bands in agreement with Mie theory. For implants with a measurable optical absorption band we used Doyle's theory and the full width half maximum of the absorption band to calculate the predicted size of the formed nanoclusters at various heat treatment temperatures. These results are compared with those obtained from direct observation using transmission electron microscopic techniques.

Microstructure and Optical Properties of Co Sputter Deposited Si-Al Nanocomposite Thin Films

2000 ◽  
Vol 648 ◽  
Author(s):  
F. Niu ◽  
P.J. Dobson ◽  
B. Cantor
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Optical Absorption ◽  
Absorption Peak ◽  
Al Content ◽  
Al Nanoparticles ◽  
Transmission Electron ◽  
Effective Medium Theories ◽  
Nanocomposite Thin Films ◽  
Sputter Deposited

AbstractNovel Si-Al nanocomposite thin films were made by radio frequency co-sputtering of Si and Al with Al content from 0 at.% to 69 at.%. Microstructure and optical properties of the films were characterised by conventional and high resolution transmission electron microscopyand spectrometry in the wavelength range from 200 to 3000 nm. The film microstructure consisted of Al nanoparticles (2-9 nm) embedded in an amorphous Si-Al matrix. Optical absorption spectra of the films up to 50 at.% Al exhibited a sharp absorption peak below500 nm and relatively low absorption above 500 nm. In addition, the absorption peak shifted towards longer wavelengths and the general absorption above 500 nm increased remarkably as Al content increased. For the Si-69at.%Al films, however, an absorption plateau appeared between 300 nm to 700 nm and a second weak and broad absorption peak appeared at around 900 nm. The results are analysed and compared with the optical absorption predicted by various effective medium theories.

Properties of Nano-layers of Nanoclusters of Ag in SiO2 Host produced by MeV Si ion bombardment

2007 ◽  
Vol 1020 ◽  
Author(s):  
C.C. Smith ◽  
S. Budak ◽  
S. Guner ◽  
C. Muntele ◽  
R. A. Minamisawa ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Absorption Band ◽  
Optical Absorption ◽  
Buffer Layer ◽  
Periodic Structure ◽  
Rutherford Backscattering Spectrometry ◽  
Bulk Material ◽  
Ion Bombardment ◽  
Optical Absorption Band ◽  
Before And After

AbstractWe prepared 50 periodic nano-layers of SiO2/AgxSiO2(1-x). The deposited multi-layer films have a periodic structure consisting of alternating layers where each layer is between 1-10 nm thick. The purpose of this research is to generate nanolayers of nanocrystals of Ag with SiO2 as host and as buffer layer using a combination of co-deposition and MeV ion bombardment taking advantage of the electronics energy deposited in the MeV ion track due to ionization in order to nucleate nanoclusters. Our previous work showed that these nanoclusters have crystallinity similar to the bulk material. Nanocrystals of Ag in silica produce an optical absorption band at about 420 nm. Due to the interaction of nanocrystals between sequential nanolayers there is widening of the absorption band. The electrical and thermal properties of the layered structures were studied before and after 5 MeV Si ions bombardment at various fluences to form nanocrystals in layers of SiO2 containing few percent of Ag. Rutherford Backscattering Spectrometry (RBS) was used to monitor the stoichiometry before and after MeV bombardments.

Comparison of the distributions of galactic y-radiation and radio synchrotron radiation

1981 ◽  
Vol 301 (1462) ◽  
pp. 573-575 ◽  
Keyword(s):  
Radio Emission ◽  
Full Width Half Maximum ◽  
Detailed Comparison ◽  
Full Width ◽  
Half Maximum ◽  
Brightness Temperatures ◽  
Point Spread ◽  
Sky Survey ◽  
Spread Function ◽  
Continuum Radio

We have used the new all-sky survey of continuum radio emission at 408 MHz of Haslam et al. (1981 a, b ) to compare the distribution of radio emission in a band along the galactic equator for [ b ] < 20° with the COS-B y-ray distribution of Mayer-Hasselwander et al. (1980). The radio survey has resolution with full width half-maximum (f.w.h.m.) of 51 arc min and the data are brightness temperatures at 20' intervals in galactic coordinates. Such comparisons have been made before (see, for example, Jakel et al. 1975; Paul et al. 1976; Higdon 1979) with earlier y-ray data but this is the first in which the radio data have been in a form allowing a detailed comparison after convolution with the point spread function of the y-ray detector.

AMMONO method of BN, AlN and GaN synthesis and crystal growth.

1998 ◽  
Vol 3 ◽  
Author(s):  
R. Dwili˜ski ◽  
R. Doradzi˜ski ◽  
J. Garczy˜ski ◽  
L. Sierzputowski ◽  
M. Palczewska ◽  
...  
Keyword(s):  
Reaction Rate ◽  
Full Width Half Maximum ◽  
Full Width ◽  
Half Maximum ◽  
Helium Temperature ◽  
Photoluminescence Spectra ◽  
Paramagnetic Resonance ◽  
Temperature And Pressure ◽  
Supercritical Ammonia ◽  
Electron Paramagnetic

Microcrystals of BN, AlN and GaN were obtained by the AMMONO method, in which nitridization of metal occurs in supercritical ammonia, at relatively low temperature and pressure conditions (below 550°C and 5 kbar). The reaction rate was regulated by the amount of mineralizers, i.e. alkali metal amides.All crystals obtained by AMMONO method revealed intense and homogenous luminescence. Significant improvement of the optical properties was observed for crystals grown in the presence of Rare Earth elements. For such GaN crystals, helium temperature photoluminescence spectra were dominated by near-band-gap recombination. Exciton lines were extremely narrow, with full-width half-maximum (FWHM) as low as 1 meV. The concentration of uncompensated shallow donors in AMMONO GaN determined by electron paramagnetic resonance measurements was below 5×1015 cm−3.

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.

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