FWHM Calculation of Zircon Gem-Materials before and after Thermal Enhancement

2017 ◽  
Vol 737 ◽  
pp. 599-603
Author(s):  
Pilantana Wattananurak ◽  
Natthapong Monarumit ◽  
Rattanawalee Chooyoung ◽  
Krit Won-In ◽  
Sutharat Chotikaprakhan ◽  
...  
Keyword(s):  
Peak Position ◽  
Molecular Vibration ◽  
Raman Shift ◽  
Blue Color ◽  
Full Width ◽  
Radioactive Elements ◽  
Zircon Structure ◽  
Thermal Enhancement ◽  
Before And After ◽  
Reducing Condition

Zircon samples from Ubon Ratchathani, Thailand; Rattanakiri, Cambodia and Dak Nong, Vietnam change their color from light brown and reddish-brown to blue color after thermal enhancement at 1000 ๐C in reducing condition for 60 min. The high temperature is one of the factors for the zircon structure to recrystallize. The objective of this study is to describe the crystal structure of zircon samples before and after thermal enhancement. Zircon is a metamict mineral whose structure is destroyed by some trace elements. There are radioactive elements such as U and Th in the zircon structure. In this study, Raman spectroscopy was used to analyze the molecular vibration in zircon structure before and after thermal enhancement. As a result, the Raman spectra of zircon samples after thermal enhancement show the Raman shift at peak position of V3(SiO4) stretching around 1008cm-1to higher wavenumber concerning to the full width at half maximum (FWHM) values calculated by PyMCA software. The results could be summarized that the metamict zircon will be recrystallized to the crystalline zircon after thermal enhancement. The advantage of this study is about the identification of zircon before and after thermal enhancement.

Molecular Vibration Theoretical Analysis of Two-Dimensional Photoelectric Conversion Material WSe2

2018 ◽  
Vol 765 ◽  
pp. 16-23
Author(s):  
Rui Zhang ◽  
Hong Bo Li ◽  
Guo Qiang Hao ◽  
Wen Bo Liu ◽  
Xiao Jun Ye ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Density Functional ◽  
Molecular Vibration ◽  
Raman Shift ◽  
Vibration Modes ◽  
Photoelectric Conversion ◽  
Functional Theory ◽  
Conversion Materials ◽  
Direct Band ◽  
New Generation

Monolayer WSe2is flexible, nearly transparent and direct band-gap semiconductor with the potential to be new generation thin film photoelectric conversion materials. The molecule vibration modes of monolayer and bulk WSe2was analyzed by factor group and the phonons dispersion and vibration frequency was calculated by first-principles based on density functional theory. Furthermore, the comparison between the above calculations and experiment values of Raman shift of monolayer and bulk WSe2was made to verify the accuracy of theoretical analysis and theoretically explain the differences of monolayer and bulk WSe2materials in Raman spectra.

Time Dependence of γ/γ' Lattice Mismatch in Creep-Deformed Single Crystal Superalloy SC16 at 1173 K

2007 ◽  
Vol 539-543 ◽  
pp. 3059-3063 ◽  
Author(s):  
G. Schumacher ◽  
N. Darowski ◽  
I. Zizak ◽  
Hellmuth Klingelhöffer ◽  
W. Chen ◽  
...  
Keyword(s):  
Single Crystal ◽  
Lattice Mismatch ◽  
Lattice Misfit ◽  
Peak Position ◽  
Single Crystal Superalloy ◽  
Tensile Creep ◽  
Full Width ◽  
X Ray Diffraction ◽  
X Ray ◽  
Time Period

The profiles of 001 and 002 reflections have been measured at 1173 K as a function of time by means of X-ray diffraction (XRD) on tensile-creep deformed specimens of single crystal superalloy SC16. Decrease in line width (full width at half maximum: FWHM) by about 7 % and increase in peak position by about 3x10-4 degrees was detected after 8.5x104 s. Broadening of the 002 peak profile indicated a more negative value of the lattice misfit after the same time period. The results are discussed in the context of the anisotropic arrangement of dislocations at the γ/γ’ interfaces during creep and their rearrangement during the thermal treatment at 1173 K.

Identification of Amber and the Copal under Heat Pressurized Process

2012 ◽  
Vol 554-556 ◽  
pp. 2112-2115
Author(s):  
Hui Li ◽  
Xuan Wang ◽  
Yong Zhu ◽  
Qin Ren
Keyword(s):  
Chemical Properties ◽  
Peak Position ◽  
Exothermic Peak ◽  
Endothermic Peak ◽  
Scanning Calorimetry ◽  
Natural Resin ◽  
Before And After ◽  
Artificial Heat ◽  
Physical And Chemical ◽  
And Chemical Properties

Amber and copal belong to the natural resin, which are similar and transitional in the physical and chemical properties. The artificial heat-pressurized treatment is contributed to the polymerization of the natural copal, and turns into green, yellow-green and deep orange-yellow copal. It is very difficult to identify amber from the heat- pressurized treatment copal only based on the gemological parameters.The thermal behavior of amber and the copal before and after heat-pressurized treatment were analyzed by means of differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy(FTIR) and nuclear magnetic resonance(NMR). The results show that amber exists an evident endothermic peak around 123~132°C, and copal reveals an obvious endothermic peak at about 174~178°C, and the heat pressurized treatment copal occurs a clear exothermic peak around 150~152°C. The differences between endothermic or exothermic transition and peak position reveal occurring thermal oxidation or the bond breaking or the melting, which are of great significance in the identification.

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.

Evolution of photoluminescence from Si nanocrystals embedded in a SiO2 matrix prepared by reactive pulsed laser deposition

2009 ◽  
Vol 24 (7) ◽  
pp. 2259-2267 ◽  
Author(s):  
Fang Fang ◽  
Wei Zhang ◽  
Jian Sun ◽  
Ning Xu ◽  
Jiang Zhu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Annealing Temperature ◽  
Pulsed Laser ◽  
Average Diameter ◽  
Peak Position ◽  
Nitrogen Atmosphere ◽  
Film Deposition ◽  
Structural Variations ◽  
Si Nanocrystals ◽  
Before And After

Photoluminescence (PL) properties of SiOx thin films deposited by pulsed laser ablation of Si in a reactive oxygen ambient and annealed in a nitrogen atmosphere were studied at room temperature. Raman spectroscopy, Fourier transform infrared spectroscopy, and optical transmission measurements were used to characterize the deposited films before and after annealing and complement the PL studies. Strong PL due to quantum confinement was observed at room temperature from Si nanocrystals with an average diameter of approximately 5 nm at 325-nm light excitation. An apparent dependence of PL on the oxygen pressure for film deposition was observed. A detailed analysis of the effects of the annealing temperature revealed a significant PL evolution in luminescence intensity, spectrum profile, peak position, and spectrum range with the annealing temperature ranging from 300 to 1200 °C. Structural variations induced by thermal annealing of the films deposited at different oxygen pressures were also discussed on the basis of their correlation with the PL evolution.

Reactive Multilayers Examined by HRTEM and Plasmon EELS Chemical Mapping

2009 ◽  
Vol 15 (1) ◽  
pp. 54-61 ◽  
Author(s):  
M.A. Mat Yajid ◽  
G. Möbus
Keyword(s):  
Electron Microscopy ◽  
High Resolution Electron Microscopy ◽  
Peak Position ◽  
Multilayer System ◽  
Chemical Mapping ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Before And After ◽  
Relationship Of ◽  
Electron Energy Loss

AbstractWe examine chemical mapping of reaction phases in a Cu-Al multilayer system using low-loss electron energy loss spectroscopy spectrum imaging and image spectroscopy techniques. The sensitivity of the plasmon peak position and shape to various crystal structures and phases is exploited using postprocessing of spectra into second derivative plasmon maps and line scans. Analytical transmission electron microscopy is complemented by studies of the orientation relationship of the multilayer system using high-resolution electron microscopy of interfaces and selected area diffraction. The techniques have been applied to the Cu-Al multilayer sample and sharply bound epitaxial phases are found, before and after heat treatment.

scholarly journals Effect of Substrate Biasing on the Epitaxial Growth and Structural Properties of RF Magnetron Sputtered Germanium Buffer Layer on Silicon

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1060
Author(s):  
Gui-Sheng Zeng ◽  
Chi-Lung Liu ◽  
Sheng-Hui Chen
Keyword(s):  
Single Crystal ◽  
Lattice Constant ◽  
High Efficiency ◽  
Buffer Layers ◽  
Crystalline Quality ◽  
Raman Shift ◽  
Full Width ◽  
Half Maximum ◽  
Si Substrates ◽  
Diffraction Patterns

High-quality single-crystal-like Ge (004) thin films have been epitaxially grown using radio-frequency magnetron sputtering on Si (001) substrates successfully. The crystalline quality of the Ge films can be obviously improved by applying a positive bias on the substrate holder. X-ray diffraction measurements show that the single-crystal-like Ge film has a narrow full width at half maximum of 0.26°. The perpendicular lattice constant (aGe⊥) and in-plane lattice constant (aGe∥) are 0.5671 and 0.564 nm. The Raman shift full width at half maximum shows that the defects in the film are obviously reduced. Transmission electron microscopy diffraction patterns also show that the Ge (004) film has good crystalline quality. The results can be applied as Ge buffer layers on Si substrates for the fabrication of high-efficiency III–V solar cells and photodetectors.

Depth distributions of heavy ions in LiNbO3 and KTiOPO4 at tilted angle implantation

1994 ◽  
Vol 72 (9-10) ◽  
pp. 550-553
Author(s):  
Ke-Ming Wang ◽  
Bo-Rong Shi ◽  
Bao-Dong Qu ◽  
Hong-Ying Zhai ◽  
Pei-Jun Ding ◽  
...  
Keyword(s):  
Heavy Ions ◽  
Peak Position ◽  
Full Width ◽  
Half Maximum ◽  
Ion Distribution ◽  
Tilted Angle ◽  
Ion Distributions ◽  
Transport Of Ions ◽  
Calculation Procedures ◽  
Depth Distributions

200 keV Hg and 1000 keV Xe ions were implanted into LiNbO3 and KTiOPO4 at a tilted angle. The depth distributions of Hg and Xe ions in LiNbO3 and KTiOPO4 were measured by Rutherford backscattering of MeV He ions. The experimental ion distributions are compared with the transport of ions in matter (TRIM'89) simulation. The result shows a slight difference in the peak position between the experimental and theoretical ion distribution, but the form of the experimental ion distribution is found to be in agreement with the theoretical one predicted by TRIM'89 except for a different width in the case of LiNbO3. The FWHM (full width at half maximum) of the experimental ion distribution is larger than the theoretical one given by TRIM'89 in the case of KTiOPO4. The lateral spreads obtained are compared using different calculation procedures.

Microstructure And Wear Resistance Of Doped Diamondlike Carbon Prepared By Pulsed Laser Deposition

1997 ◽  
Vol 505 ◽  
Author(s):  
Q. Wei ◽  
R. J. Narayan ◽  
A. K. Sharma ◽  
S. Oktyabrsky ◽  
J. Sankar ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
Photoelectron Spectroscopy ◽  
Wear Behavior ◽  
Pulsed Laser ◽  
Peak Position ◽  
Raman Shift ◽  
Dlc Coatings ◽  
Diamondlike Carbon ◽  
Metal Doped

ABSTRACTWe have investigated the microstructure and tribological properties (wear resistance) of diamondlike carbon (DLC), DLC doped with Cu and DLC doped with Ti deposited by a sequential pulsed laser ablation of two targets onto Si(100) substrates. The composition of these films was determined by Rutherford backscattering spectroscopy and X-ray photoelectron spectroscopy(XPS). Raman spectroscopy and detailed analysis of the electron diffraction pattern of the films showed typical features of DLC with a structure dominated by sp3 bonded carbon. Wear resistance measurements made on these samples by means of the “crater grinding method” showed that DLC + 2.75%Ti has the highest wear resistance, while that of undoped DLC has the lowest among the samples. The improvement of wear behavior of the doped films was attributed to the reduction of internal compressive stress due to the presence of more compliant atoms, as indicated by the G-peak position shift to smaller Raman shift. The XPS studies showed the evidence for the formation of Ti- C bonding in the Ti doped films. Thus we expect metal-doped DLC coatings can have better tribological properties than the undoped, highly stressed DLC coatings.

Photoluminescence from Silicon Nanocrystals Formed by Pulsed-Laser Deposition

2003 ◽  
Vol 770 ◽  
Author(s):  
X. Y. Chen ◽  
Y. F. Lu ◽  
Y. H. Wu ◽  
B. J. Cho ◽  
W. D. Song ◽  
...  
Keyword(s):  
Ambient Pressure ◽  
Quantum Confinement Effect ◽  
Surface States ◽  
Peak Shift ◽  
Peak Position ◽  
Small Crystals ◽  
Before And After ◽  
Intensity Changes ◽  
Excitation Laser ◽  
Ar Gas

AbstractSi nanocrystals (NCs) consisting of small crystals from 1 to 20 nm were formed by pulsedlaser deposition (PLD) in inert Ar gas and reactive O2 gas. The oxygen content of the Si NCs increases with increasing O2 ambient pressure and nearly SiO2 stoichiometry is obtained when O2 pressure is higher than 100 mTorr. The optical absorption of the Si NCs shows an indirect band transition. Broad PL spectra are observed from Si NCs. The peak position and intensity of the PL band at 1.8–2.1 eV are dependent on excitation laser intensity, while intensity changes and blue shifts are observed after oxidation and annealing. The PL band at 2.55 eV displays vibronic structures with periodic spacing of 97 ± 9 meV, while no peak shift is found before and after oxidation and annealing. The as-deposited Si NCs show a polycrystal structure and crystallinity improves after annealing. Combined with the PL of Si NCs obtained by crumbling electrochemical-etched porous Si layer, the results give strong evidence that the PL band at 1.8–2.1 eV is due to the quantum confinement effect (QCE) in Si NC core while the PL band at 2.55 eV is related to the localized surface states at SiOx/Si interface.

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