scholarly journals Evaluation of Relationship between Grain Morphology and Growth Temperature of HgI2 Poly-Films for Direct Conversion X-ray Imaging Detectors

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 32
Author(s):  
Gang Xu ◽  
Ming Yao ◽  
Mingtao Zhang ◽  
Jinmeng Zhu ◽  
Yongxing Wei ◽  
...  
Keyword(s):  
Grain Size ◽  
Growth Temperature ◽  
Physical Vapor Deposition ◽  
Grain Morphology ◽  
Growth Period ◽  
Direct Conversion ◽  
Polycrystalline Film ◽  
X Ray ◽  
Imaging Detectors ◽  
The Relationship

The relationship between depositing temperature and crystallinity of grain for HgI2 polycrystalline film with 170 cm2 in area deposited by Physical Vapor Deposition (PVD) was investigated, considering the matches with readout matrix pixelation for female breast examination. The different depositing temperatures, 35, 40 and 45 °C, were carried out with the same source temperature, 100 °C, corresponding to 2–2.5 h of the growth period. The films deposited were investigated by XRD, SEM, and I–V. The results show that the grain size of the films grown increases with the depositing temperature from 35 to 45 °C. At 45 °C, the polycrystalline film has a preferred microcrystal orientation with 97.2% of [001]/[hkl] and grain size is about 180–220 μm. A 256 × 256 pixels X-ray image of a bolt, key, and wiring displacement was present distinctly with 50 keV with 6 mA current of X-ray generator. Our discussions on the relationship between depositing temperature and crystallinity of grain of film suggest that the higher growth temperature, the better crystallinity and excellent preferred microcrystal orientation of grain, however, with complementary bigger grain size. For matching readout matrix pixelation, the growth period of poly-films would be reduced appropriately for reasonable grain size and preventing the crack of films deposited.

Critical Laser Fluence Observed in (111) Texture, Grain Size and Mobility of Laser Crystallized Amorphous Silicon

1993 ◽  
Vol 297 ◽  
Author(s):  
R.I. Johnson ◽  
G.B. Anderson ◽  
J.B. Boyce ◽  
D.K. Fork ◽  
P. Mei ◽  
...  
Keyword(s):  
Grain Size ◽  
Film Thickness ◽  
Substrate Temperature ◽  
Amorphous Silicon ◽  
Laser Fluence ◽  
Laser Energy ◽  
X Ray ◽  
Peak Intensity ◽  
Silicon Materials ◽  
The Relationship

This paper describes new results on the relationship between the grain size, mobility, and Si (111) x-ray peak intensity of laser crystallized amorphous silicon as a function of the laser fluence, shot density, substrate temperature, and film thickness. These observations include an unexpected narrow peak found in the silicon (111) x- ray peak intensity, which occurs at a specific laser fluence for a given film thickness and substrate temperature. Amorphous silicon materials processed at laser energy densities defined by this peak exhibit exceptionally large grain sizes and electron mobilities that cannot be obtained at any other energy and shot density combination above or below the energy at which the Si (111) x-ray peak intensity maximum occurs.

scholarly journals X-Ray Stress Measurement of Carbide in Tool Steel

2005 ◽  
Vol 490-491 ◽  
pp. 281-286
Author(s):  
Masahide Gotoh ◽  
Hajime Hirose ◽  
Toshihiko Sasaki
Keyword(s):  
Thin Film ◽  
Residual Stress ◽  
Plastic Strain ◽  
Tool Steel ◽  
Physical Vapor Deposition ◽  
Stress Measurement ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
X Ray ◽  
The Relationship

Thin films deposited by physical vapor deposition (PVD) were studied in terms of residual stress by the authors. The final purpose of our study is to evaluate the stress state at the interface between a substrate and a thin film. In this study, JIS-SKH55 tool steel without thin-film deposition was used as the specimen. SKH55 is a dual-phase steel consisting of martensite a’Fe and alloyed carbide M6C2. The specimens were heated to 573K, 798K, 843K and 893K. Recently, the relationship between the misfit of plastic strain and stress obtained by X-ray stress measurement has been proposed by the authors using the Eshelby/Mori-Tanaka model (EMT model). The residual stress and the misfit of plastic strain were determined by X-ray stress measurement using the EMT model. Results showed that as annealing temperature increased, the compressive residual stress remained nearly constant up to about 800K, and decreased above 800K in both phases. The misfit of plastic strain also remained nearly constant up to about 800K, and reached zero above 800K.

Effects of pressure, temperature, and grain size on the kinetics of the calcite → aragonite transformation

1979 ◽  
Vol 16 (7) ◽  
pp. 1402-1418 ◽  
Author(s):  
N. S. Brar ◽  
H. H. Schloessin
Keyword(s):  
Grain Size ◽  
Single Crystals ◽  
Relative Increase ◽  
Surprising Result ◽  
X Ray ◽  
Mass Fractions ◽  
Deviatoric Stresses ◽  
The Relationship ◽  
Kinetics Of ◽  
Iceland Spar

Single crystals and polycrystalline samples of transparent calcite (Iceland spar) were used to investigate the effects of pressure (p), temperature (T), pressure beyond an accepted equilibrium value (Δp), and grain size (D) on the kinetics of the calcite–aragonite transformation. Transformed mass fractions x(t), produced after different times of exposure to constant pressure ranging from 14 to 25 kbar (1.4 to 2.5 GPa) and constant temperature from 300 to 600 °C, were determined from integrated X-ray peak intensities of the (012), (021), and (111) reflections of aragonite. Values for the rale constant K and the exponent n characterizing the transformation were computed from the x(t) data using Cahn's nucleation and growth model for solid–solid transformations. At 17 kbar(1.7 GPa), K(s−1) increases from 2.00 × 10−5 at 300 °C to 1.39 × 10−3 at 600 °C. The exponent n, of the order of 1, mostly <1, indicates that the nucleation stage is terminated rapidly by site saturation and that most of the transformation takes place thereafter by growth as expected from theory. For single crystals the relationship between x(t) and Δp, for a period of 1 hour is almost linear. At 600 °C the relative increase of x(t) amounts to 0.1 kbar−1 (1 × 107 Pa−1). For a given time, x increases nearly exponentially with T. The apparent activation energy for the transformation, at 17 kbar (1.7 GPa), is 16 kcal mol−1. For polycrystals x(t) decreases as [Formula: see text]. This somewhat surprising result may be related to deviatoric stresses and stress concentration by the already transformed volume fractions, which act as misfitting, ellipsoidal, inclusions.

Effect of Cu on the Microstructure and the Property of Al-Ce-Ni-Cu Amorphous Nanocomposite Materials

2012 ◽  
Vol 624 ◽  
pp. 248-251
Author(s):  
Hong Wei Zhang ◽  
Can Bang Zhang ◽  
Li Li Zhang ◽  
Feng Rui Zhai ◽  
Jia Jin Tian
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Grain Size ◽  
Annealing Temperature ◽  
Nanocomposite Materials ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Nano Composite ◽  
X Ray ◽  
The Relationship

Preparing amorphous alloy of Al87Ce3Ni10-xCux（x=0,1,3,5）with single roller spin quenching technology, after annealing the alloy for 20 minutes at 180 degrees Celsius, 200 degrees Celsius, 220 degrees Celsius and 240 degrees Celsius, and then the nanocomposites can be obtained. he microhardness of amorphous nano-composite materials are measured .The microstructure, grain size of , thermal stability, midrohardness are related with the annealing temperature and the composition of alloy, and studying the relationship between them by X-ray diffraction (XRD) and differential scanning calorimetry (DSC).The present results indicated that with the increase of the content of Cu, the grain size of decreases, the increasing of the microhardness is due to the grain refinement: with the increase of the content of Cu, precipitation temperature of moves to low, which is helpful for the precipitation of phase.

Direct-conversion x-ray imaging detectors for medical nondestructive testing (NDT) and other applications

2001 ◽  
Author(s):  
Denny L. Y. Lee ◽  
Kelly P. Golden ◽  
Jeffrey G. Yorker ◽  
Brian G. Rodricks ◽  
Lawrence K. Cheung ◽  
...  
Keyword(s):  
Nondestructive Testing ◽  
Direct Conversion ◽  
X Ray ◽  
X Ray Imaging ◽  
Imaging Detectors

scholarly journals Phase Relations inBa6−3xLn8+2xTi18O54(Ln = Nd & Sm) Electroceramics

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Amanda L. Snashall ◽  
Yun Liu ◽  
Frank Brink ◽  
Ray L. Withers ◽  
Steven Cooper
Keyword(s):  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Grain Morphology ◽  
Secondary Phase ◽  
Systematic Investigation ◽  
Phase Relations ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Dielectric ◽  
The Relationship

A careful, systematic investigation ofBa6−3xLn8+2xTi18O54(BLnTss) ceramics has been performed in order to understand the relationship between composition, microstructure evolution, and microwave dielectric properties. In this paper, we report the effects of composition, morphology, and sintering time on the phase relations and properties of BLnTss (Ln = Nd, Nd/Sm, Sm) ceramics. The microwave dielectric properties of the materials are reported in addition to phase characterisation and structural analysis via X-ray diffraction and field emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. BLnTss,x=0.33, ceramics with high Sm content are found to experience a severe degradation of Qf and changes inτcftrending, associated with the onset of globular and needle-like grain morphology and a Ba-Ti rich phase.x=0.67ceramics with high Nd content are found to exhibit a secondary phase (Nd2Ti2O7) upon prolonged sintering which resulted in beneficial changes to Qf andτcfwithout affectingεr. Two BLnTss ceramics compositions with near-zeroτcfwere successfully synthesised with high Qf andεrvalues.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

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