scholarly journals Investigation of Y2.1Er0.9(ScxGa1−x)5O12 Matrix Components on the Spectral Properties around 3.0 μm by Micro-Pulling-Down Method

Crystals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 138
Author(s):  
Zhijiang Che ◽  
Jian Zhang ◽  
Baiyi Wu ◽  
Qiangqiang Hu ◽  
Wenxiang Mu ◽  
...  
Keyword(s):  
Fluorescence Spectra ◽  
Room Temperature ◽  
Lattice Vibration ◽  
Emission Spectra ◽  
X Ray Diffraction ◽  
Mid Infrared ◽  
X Ray ◽  
Electron Probe Microanalyzer ◽  
The Matrix ◽  
Crystal Fibers

Single crystal fibers of 30% Er3+-doped compound of Y3(ScxGa1−x)5O12 have been grown by using the micro-pulling down (μ-PD) technique successfully. Our main purpose is to tune the fluorescence properties by adjusting the ratios of Sc3+ and Ga3+ ions inside the matrix crystals. The crystal structures of the series compounds were measured and analyzed through X-ray diffraction (XRD) measurements. The components and doping elements distributions were measured by the X-ray Fluorescence spectrometry and electron-probe microanalyzer. The absorption and mid-infrared fluorescence spectra, including the fluorescent lifetime of Er3+:4I13/2 and 4I11/2 levels were measured and compared systematically at room temperature. Spectral analysis indicated that the fluorescent lifetime of Er3+:4I13/2 tended to shorten and the emission spectra began to show a red shift when the proportion of YSG increased in the compound. Furthermore, the Raman spectra were measured to reveal the variations of lattice vibration and phonon energy.

Direct Interaction of Colloidal Nanostructured ZnO and SnO2 with NO and SO2

2008 ◽  
Vol 8 (12) ◽  
pp. 6389-6397 ◽  
Author(s):  
D. Velasco-Arias ◽  
D. Díaz ◽  
P. Santiago-Jacinto ◽  
G. Rodríguez-Gattorno ◽  
A. Vázquez-Olmos ◽  
...  
Keyword(s):  
Electronic Absorption ◽  
Room Temperature ◽  
Emission Spectra ◽  
Direct Interaction ◽  
X Ray Diffraction ◽  
Wurtzite Phase ◽  
X Ray ◽  
Spontaneous Hydrolysis ◽  
Uv Visible ◽  
Hydrolysis Of

A novel and easy synthesis pathway of small SnO2 nanoparticles is reported. The method consists of the spontaneous hydrolysis of SnCl4·5H2O in dimethyl sulfoxide (DMSO), containing 3% water, at room temperature. The structure of the SnO2 nanocrystals corresponds to that of the cassiterite phase, as shown by powder X-ray diffraction and HR-TEM. The UV-visible electronic absorption and emission spectra of the SnO2 colloids are discussed. The reactions of NO(g) and SO2(g) with ZnO (wurtzite phase) and SnO2 nanocolloids are studied. The interaction of NO with ZnO nanoparticles generates the dissolution of the particles and it is quite probable that NO−13, NO−12, N2O and N2 are formed; while its contact with SO2 probably yields SO−24, SO−23 and also the dissolution of the particles is observed. When these gases are reacted with SnO2, then NO−13, NO−12, SO−23 and SO−24, were respectively obtained.

Macro-and Microstrain Relaxation in Annealed Ag Films During Ageing at Room Temperature

1997 ◽  
Vol 505 ◽  
Author(s):  
R. C. Currie ◽  
R. Delhez ◽  
E. J. Mitiemeijer
Keyword(s):  
Room Temperature ◽  
Strain Relaxation ◽  
Diffraction Line ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
Thermally Induced ◽  
X Ray ◽  
Diffraction Line Profile ◽  
The Matrix ◽  
Profile Position

ABSTRACTThe relaxation of thermally induced strain in 500 nm thick polycrystalline Ag layers electron-beam deposited onto Si wafers was traced during ageing at room temperature. The layers consisted predominantly of matrix crystallites with {111} planes parallel to the surface and twin crystallites with {51 l} planes parallel to the surface. The macrostrain in the plane of the layer was determined from the X-ray diffraction line-profile position and the microstrain from the diffraction-line broadening. The residual macrostress relaxed from 160 MPa to 30 MPa in the matrix crystallites and from 170 MPa to 50 MPa in the twin crystallites. Simultaneously with the decrease in macrostress the microstrain decreases significantly for both texture fractions. The strain relaxation behaviour is governed by movement and subsequent annihilation of defects in the layer.

Tribological behaviour of AZ91D/ultra-high-temperature ceramic composites at room and elevated temperatures

2021 ◽  
pp. 135065012110100
Author(s):  
KT Sunu Surendran ◽  
A Gnanavelbabu
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Wear Test ◽  
X Ray Diffraction ◽  
Tribological Behaviour ◽  
X Ray ◽  
The Matrix ◽  
Scanning Electron ◽  
Ultra High Temperature

In this research work, the tribological behaviour of an AZ91D alloy and its composites reinforced with different titanium-based ultra-high-temperature ceramic particulates was investigated. Titanium-based ultra-high-temperature ceramic materials (5 wt%) such as titanium carbide, titanium boride and titanium nitride was used for the fabrication of three different composites, namely ATC, ATB and ATN, respectively. The proposed composites were prepared using a novel ultrasonic treatment-assisted stir-squeeze casting technique. Material characterization was performed using scanning electron microscopy and X-ray diffraction techniques. The porosity and hardness of the composites were determined prior to the wear test. In the pin-on-disc tribometer, the wear test was carried out at room temperature by varying the normal load (12.5–50 N) and the sliding speed (0.25–1 m/s). In addition, at a temperature of up to 200 °C, the tribological behaviour of the composites was assessed. The homogeneous distribution of ultra-high-temperature ceramic particles in the matrix was confirmed by the analysis of the microstructure using scanning electron microscopy images. The X-ray diffraction results showed that the reinforcement materials in the matrix were thermally stable. The hardness of the ATC, ATB and ATN was improved by approximately 31%, 33.8% and 29.6%, respectively. In comparison, at all wear testing conditions, ATB demonstrated superior tribological performance, while the performance of ATN was poor and ATC was moderate. Abrasion, oxidation and delamination were the wear mechanisms at room temperature. At elevated temperatures, oxidation, delamination, thermal softening and plastic deformation wear mechanisms were significant..

Synthesis and spectroscopic studies of Tm3+-doped KY3F10 single crystals

2000 ◽  
Vol 77 (9) ◽  
pp. 693-697 ◽  
Author(s):  
M Diaf ◽  
A Braud ◽  
C Labbé ◽  
J L Doualan ◽  
S Girard ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Room Temperature ◽  
Laser Emission ◽  
Emission Spectra ◽  
Branching Ratios ◽  
Spectroscopic Studies ◽  
Luminescence Decay ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Time

We examine the laser possibilities offered by Tm3+-doped KY3F10. After crystal growth and X-ray diffraction analysis, the optical properties of thulium ions in KY3F10 are determined for the first time. Absorption and emission spectra recorded at low temperatures are used to obtain a set of Stark sublevels, whereas the room-temperature absorption spectra have been allowed to fit the three phenomenological Judd-Ofelt (JO) parameters. The emission line strengths, branching ratios, and radiative lifetimes of levels from 3F4 up to 1D2 are then deduced. A comparison between the calculated lifetimes and the measured luminescence decay curves permits us to check the reliability of the JO analysis for this system. The potential of Tm:KY3F10 for laser emission from 3H4 or 3F4 emitting levels is briefly examined.PACS Nos.: 42.55.Rz, 78.50.Ec, 78.47.+p, 81.10.Fq.

Accidental formation of Gd4(SiO4)2OTe: crystal structure and spectroscopic properties

2015 ◽  
Vol 71 (7) ◽  
pp. 598-601 ◽  
Author(s):  
Marek Daszkiewicz ◽  
Lubomir D. Gulay
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Room Temperature ◽  
Emission Spectra ◽  
Functional Materials ◽  
Spectroscopic Properties ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Interest In Science

Designing new functional materials with increasingly complex compositions is of current interest in science and technology. Complex rare-earth-based chalcogenides have specific thermal, electrical, magnetic and optical properties. Tetragadolinium bis[tetraoxidosilicate(IV)] oxide telluride, Gd4(SiO4)2OTe, was obtained accidentally while studying the Gd2Te3–Cu2Te system. The crystal structure was determined by means of single-crystal X-ray diffraction. The compound crystallizes in the space groupPnma. Three symmetry-independent gadolinium sites were determined. The excitation and emission spectra were collected at room temperature and at 10 K. Gd4(SiO4)2OTe appears to be a promising optical material when doped with rare-earth ions.

scholarly journals High-Temperature X-Ray Diffraction and Fluorescence Spectra of SnSe Single Crystal

2019 ◽  
Vol 73 (6) ◽  
pp. 519-524
Author(s):  
Jahangir Huseynov ◽  
Rena Mamedova ◽  
Ibrahim Abbasov ◽  
Dunyameddin Askerov ◽  
Khaver Sadig
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Fluorescence Spectra ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Stockbarger Method

Abstract The temperature dependence of unit cell parameters was studied using high-temperature X-ray diffraction and the coefficient of thermal expansion of SnSe single crystal was determined. Fluorescence spectra of SnSe single crystal grown by the Bridgman-Stockbarger method were examined using a Cary Eclipse spectrophotometer at room temperature in the wavelength range 200–900 nm. When the samples were irradiated by a pulse at a wavelength of 230 nm, the fluorescence spectra exhibited maxima at wavelengths 313.07, 423.03, 458.93, 495.07, and 530.00 nm.

X Ray Topography Study of Deformed Crystal-Quasicrystal Composites of Al Cu Fe Alloy

2010 ◽  
Vol 163 ◽  
pp. 278-281 ◽  
Author(s):  
Włodzimierz Bogdanowicz ◽  
Jacek Krawczyk
Keyword(s):  
Optical Microscopy ◽  
Phase Analysis ◽  
Misorientation Angle ◽  
Tensile Strain ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
The Matrix ◽  
Powder Phase

Crystal-quasicrystal columnar composites (CQ composites) of Al Cu Fe alloy subject to tensile strain at room temperature were studied by the reflective X ray topography. In those composites singlecrystalline β phase occurred as the matrix and rods consisting of quasicrystalline ψ phase and crystalline λ phase as the reinforcement. X-ray topograms of plate like composite specimens were obtained using reflexes of singlecrystalline matrix. It has been found that at strains ε up to 0.33% in a linear range of stress strain σ(ε) relationship the topograms remain unchanged. Instead, at ε higher than 0.33% significant contract changes have been observed in some areas of topograms. It has been determined that at ε higher than 0.33% the components of misorientation angle of those areas increase with increasing strain. Methods of powder phase analysis, metallographic examinations by means of optical microscopy methods and X-ray diffraction topography methods were used.

Electron Microscopy of Human Gallstones

1971 ◽  
Vol 29 ◽  
pp. 296-297
Author(s):  
C. Wolpers ◽  
R. Blaschke
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bile Pigment ◽  
X Ray Diffraction ◽  
Triclinic Crystal System ◽  
X Ray ◽  
Follow Up Study ◽  
Infra Red ◽  
Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

Raman And Fluorescence Spectra Observed in Laser Microprobe Measurements of Several Compositions in the Ln-Ba-Cu-O System

1990 ◽  
Vol 48 (2) ◽  
pp. 278-279
Author(s):  
Edgar S. Etz ◽  
Thomas D. Schroeder ◽  
Winnie Wong-Ng
Keyword(s):  
Fluorescence Spectra ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Raman Microprobe ◽  
Methods Of Synthesis ◽  
Compositional Homogeneity ◽  
Processing Techniques

We are investigating by Raman microprobe measurements the superconducting and related phases in the LnBa2Cu3O7-x (for x=0 to 1) system where yttrium has been replaced by several of the lanthanide (Ln = Nd,Sm,Eu,Ho,Er) elements. The aim is to relate the observed optical spectra (Raman and fluorescence) to the compositional and structural properties of these solids as part of comprehensive materials characterization. The results are correlated with the methods of synthesis, the processing techniques of these materials, and their superconducting properties. Of relevance is the substitutional chemistry of these isostructural systems, the differences in the spectra, and their microanalytical usefulness for the detection of impurity phases, and the assessment of compositional homogeneity. The Raman spectra of most of these compounds are well understood from accounts in the literature.The materials examined here are mostly ceramic powders prepared by conventional solid state reaction techniques. The bulk samples are of nominally single-phase composition as determined by x-ray diffraction.

Electron Microscope study of commensurate-incommensurate phase transition in BaZnGeO4

1990 ◽  
Vol 48 (4) ◽  
pp. 172-173
Author(s):  
Naoki Yamamoto ◽  
Makoto Kikuchi ◽  
Tooru Atake ◽  
Akihiro Hamano ◽  
Yasutoshi Saito
Keyword(s):  
Phase Transition ◽  
Electron Microscope Study ◽  
Room Temperature ◽  
Hexagonal Lattice ◽  
Ferroelectric Materials ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Periodic Arrays ◽  
Modulation Wave Vector

BaZnGeO4 undergoes many phase transitions from I to V phase. The highest temperature phase I has a BaAl2O4 type structure with a hexagonal lattice. Recent X-ray diffraction study showed that the incommensurate (IC) lattice modulation appears along the c axis in the III and IV phases with a period of about 4c, and a commensurate (C) phase with a modulated period of 4c exists between the III and IV phases in the narrow temperature region (—58°C to —47°C on cooling), called the III' phase. The modulations in the IC phases are considered displacive type, but the detailed structures have not been studied. It is also not clear whether the modulation changes into periodic arrays of discommensurations (DC’s) near the III-III' and IV-V phase transition temperature as found in the ferroelectric materials such as Rb2ZnCl4.At room temperature (III phase) satellite reflections were seen around the fundamental reflections in a diffraction pattern (Fig.1) and they aligned along a certain direction deviated from the c* direction, which indicates that the modulation wave vector q tilts from the c* axis. The tilt angle is about 2 degree at room temperature and depends on temperature.

Sign in / Sign up

Export Citation Format

Share Document