New method and treatment technique applied to interband transition in GaAs1−x Px ternary alloys

Open Physics ◽  
2011 ◽  
Vol 9 (3) ◽  
Author(s):  
Cristina-Mihaela Băleanu ◽  
Raoul Nigmatullin ◽  
Saime Cetin ◽  
Dumitru Băleanu ◽  
Suleyman Ozcelik
Keyword(s):  
Room Temperature ◽  
Interband Transition ◽  
The Other ◽  
Ternary Alloys ◽  
New Method ◽  
Treatment Technique ◽  
Nonlinear Fitting ◽  
Wide Range ◽  
Fitting Parameters ◽  
Good Agreement

AbstractIn this paper we presented a new method (Eigen-Coordinates (ECs)) that can be used for calculations of the critical points (CPs) energy of the interband-transition edges of the heterostructures. This new method is more accurate and complete in comparison with conventional ones and has a wide range of application for the calculation of the fitting parameters related to nontrivial functions that initially have nonlinear fitting parameters that are difficult to evaluate. The new method was applied to determine the CPs energies from the dielectric functions of the MBE grown GaAs1−xPx ternary alloys obtained using spectroscopic ellipsometry (SE) measurements at room temperature in the 0.5-5 eV photon energy region. The obtained results are in good agreement with the results of the other methods.

Electron microscope studies of the plastic deformation of ternary alloys based on GaAs

1990 ◽  
Vol 48 (4) ◽  
pp. 1120-1120
Author(s):  
R. Haswell ◽  
U. Bangert ◽  
P. Charsley
Keyword(s):  
Plastic Deformation ◽  
Electron Microscope ◽  
Room Temperature ◽  
Stacking Faults ◽  
The Other ◽  
Ternary Alloys ◽  
Dislocation Mobility ◽  
Semiconducting Materials ◽  
Micro Indentation

A knowledge of the behaviour of dislocations in semiconducting materials is essential to the understanding of devices which use them . This work is concerned with dislocations in alloys related to the semiconductor GaAs . Previous work on GaAs has shown that microtwinning occurs on one of the <110> rosette arms after indentation in preference to the other . We have shown that the effect of replacing some of the Ga atoms by Al results in microtwinning in both of the rosette arms.In the work to be reported dislocations in specimens of different compositions of Gax Al(1-x) As and Gax In(1-x) As have been studied by using micro indentation on a (001) face at room temperature . A range of electron microscope techniques have been used to investigate the type of dislocations and stacking faults/microtwins in the rosette arms , which are parallel to the [110] and [10] , as a function of composition for both alloys . Under certain conditions microtwinning occurs in both directions . This will be discussed in terms of the dislocation mobility.

Cholinium-amino acid based ionic liquids: a new method of synthesis and physico-chemical characterization

2015 ◽  
Vol 17 (32) ◽  
pp. 20687-20698 ◽  
Author(s):  
Serena De Santis ◽  
Giancarlo Masci ◽  
Francesco Casciotta ◽  
Ruggero Caminiti ◽  
Eleonora Scarpellini ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Amino Acid ◽  
Room Temperature ◽  
Chemical Characterization ◽  
New Method ◽  
Room Temperature Ionic Liquids ◽  
Synthetic Method ◽  
Chemical Structures ◽  
Physico Chemical ◽  
Wide Range

Fourteen cholinium-amino acid based room temperature ionic liquids were prepared using a cleaner synthetic method. Chemicophysical properties were well correlated with the wide range of amino acid chemical structures.

Diversification of α–Ketoamides via Transamidation Reactions with Alkyl and Benzyl Amines at Room Temperature

2021 ◽  
Author(s):  
Shweta Singh ◽  
Sureshbabu Popuri ◽  
Qazi Mohammad Junaid ◽  
Sabiah Shahul Hameed ◽  
Jeyakumar Kandasamy
Keyword(s):  
Room Temperature ◽  
The Other ◽  
Alkyl Amines ◽  
Other Hand ◽  
Wide Range

A wide range of N-tosyl α–ketoamides underwent transamidation with various alkyl amines in the absence of catalyst, base, or additives. On the other hand, transamidation in N-Boc α–ketoamides is achieved...

scholarly journals Performance of WVSS-II hygrometers on the FAAM research aircraft

2015 ◽  
Vol 8 (3) ◽  
pp. 1617-1625 ◽  
Author(s):  
A. K. Vance ◽  
S. J. Abel ◽  
R. J. Cotton ◽  
A. M. Woolley
Keyword(s):  
Liquid Water ◽  
The Other ◽  
Optimal Conditions ◽  
Statistical Assessment ◽  
Free Data ◽  
Variable Nature ◽  
Wide Range ◽  
Research Aircraft ◽  
Using Data ◽  
Good Agreement

Abstract. We compare the performance of five hygrometers fitted to the Facility for Airborne Atmospheric Measurement's (FAAM) BAe 146-301 research aircraft using data from approximately 100 flights executed over the course of 2 years under a wide range of conditions. Bulk comparison of cloud free data show good agreement between chilled mirror hygrometers and a WVSS-II fed from a modified Rosemount inlet, but that a WVSS-II fed from the standard flush inlet appears to over-read compared to the other instruments, except at higher humidities. Statistical assessment of hygrometer performance in cloudy conditions is problematic due to the variable nature of clouds, so a number of case studies are used instead to investigate the performance of the hygrometers in sub-optimal conditions. It is found that the flush inlet is not susceptible to either liquid or solid water but that the Rosemount inlet has a significant susceptibility to liquid water and may also be susceptible to ice. In all conditions the WVSS-II responds much more rapidly than the chilled mirror devices, with the flush inlet-fed WVSS-II being more rapid than that connected to the Rosemount.

Optical Properties of MBE-Grown Gainassb

1990 ◽  
Vol 216 ◽  
Author(s):  
Wengang Bi ◽  
Aizhen Li ◽  
Songsheng Tan
Keyword(s):  
Room Temperature ◽  
Optical Band Gap ◽  
Interband Transition ◽  
Fundamental Absorption Edge ◽  
Transition Theory ◽  
Absorption Properties ◽  
Gaas Substrates ◽  
Semiconductor Alloy ◽  
Infrared Spectrometer ◽  
Good Agreement

ABSTRACTThe infrared optical absorption properties near and above the fundamental absorption edge of MBE grown undoped GaInAsSb quaternary semiconductor alloy deposited on GaSb and GaAs substrates have been measured and analyzed at room temperature by means of a Fourier Transform Infrared Spectrometer, and were found to be fully characterized by the interband transition theory and Urbach's rule. The optical band gap of MBE-GaInAsSb has been determined using a linear extrapolation of (ɑhv )2 as a function of the photon energy hv, and the refractive index n deduced from the interference pattern, which shows good agreement with the theory of Sadao Adachi's.

Structural Phase Transition in Tetrafluoroaluminates

1982 ◽  
Vol 21 ◽  
Author(s):  
J.M. Launay ◽  
J.Y. Laval ◽  
A. Gibaud ◽  
A. Bulou ◽  
J. Nouet
Keyword(s):  
Electron Diffraction ◽  
Room Temperature ◽  
Structural Phase ◽  
The Other ◽  
Electron Diffraction Data ◽  
Temperature Phase ◽  
X Ray ◽  
Quadratic Phase ◽  
Low Temperature Phase ◽  
Good Agreement

ABSTRACTIt is shown that the detailed investigation of an irreversible SPT implies the combination of X-ray, neutron and electron diffraction data. This diffraction analysis is applied to K Al F4 and Rb Al F4. There is a good agreement between the three diffraction techniques in the case of Rb Al F4 where the SPT is reversible. On the other hand, for K Al F4 room temperature quadratic phase, electron diffraction exhibits exta spots which are not evidenced by X-ray and neutron diffraction. Finally the assumption of an orthorombic lattice from neutron scattering for the low temperature phase is consistant with electron diffraction results.

Pb-free solders: Predicting of some physicochemical properties of Ag–Cu–Sn material at different temperatures

2016 ◽  
Vol 15 (07) ◽  
pp. 1650062 ◽  
Author(s):  
Rachida M’chaar ◽  
Mouloud El Moudane ◽  
Abdelaziz Sabbar ◽  
Ahmed Ghanimi
Keyword(s):  
Surface Tension ◽  
Physicochemical Properties ◽  
Molar Volume ◽  
The Other ◽  
Ternary Alloys ◽  
Other Hand ◽  
Different Temperatures ◽  
Experimental Values ◽  
Increasing Temperature ◽  
Good Agreement

In this paper, the surface tension, molar volume and density of liquid Ag–Cu–Sn alloys have been calculated using Kohler, Muggianu, Toop, and Hillert models. In addition, the surface tension and viscosity of the Ag–Cu–Sn ternary alloys at different temperatures have been predicted on the basis of Guggenheim and Seetharaman–Sichen equations, respectively. The results show that density and viscosity decrease with increasing tin and increasing temperature for the all studied models. While the surface tension shows a different tendency, especially for the Kohler and Muggianu symmetric models. On the other hand, the molar volume increases with increase of temperature and tin compositions. The calculated values of surface tension and density of Ag–Cu–Sn alloys are compared with the available experimental values and a good agreement was observed.

Beyond empiricism: Quantitative models for the permeability of heterogeneous magmas

2020 ◽  
Author(s):  
Jérémie Vasseur ◽  
Fabian Wadsworth ◽  
Donald Dingwell
Keyword(s):  
Percolation Theory ◽  
Volcanic Rocks ◽  
Large Database ◽  
3 Dimensional ◽  
Wide Range ◽  
Universality Classes ◽  
Flow Through ◽  
Overlapping Spheres ◽  
Fitting Parameters ◽  
Good Agreement

&lt;p&gt;Measurements abound for the permeability of volcanic rocks, high temperature magmas, synthetic analogues for magma and rock, and 3-dimensional domains of porous media simulated numerically. Despite a wealth of data, the dominant approach to parameterisation has been empirical, and scarcely goes beyond the power-law models for percolating systems. Here we propose a suite of methods to bring the data for these complex systems in line with theoretically grounded percolation models. To do this we create numerical samples using variations on theme of overlapping spheres filling volumes. In order to create a wide range of possible geometries, we can either define the spheres as the pore phase, or the inter-sphere volume as the pore phase, such that one option is the inverse of the other. In either case, we simulate fluid flow through the pore phase until steady state, to determine the Darcian and inertial permeability tensors. We compare these results with derived, fully theoretical percolation theory and find good agreement without fitting parameters. In order to render this useful for understanding permeability in volcanic scenarios, we compare these validated models to a large database of compiled published permeability data. This approach allows us to group the permeability of magmas into three universality classes, which each have just one dimensionless solution: (1) initially granular magmas, such as variably welded ignimbrites or tuffisites, and (2) bubbly magmas, such as pumice.&lt;/p&gt;

scholarly journals Performance of WVSS-II hygrometers on the FAAM Research Aircraft

2014 ◽  
Vol 7 (8) ◽  
pp. 8643-8667 ◽  
Author(s):  
A. K. Vance ◽  
S. J. Abel ◽  
R. J. Cotton ◽  
A. M. Woolley
Keyword(s):  
Liquid Water ◽  
The Other ◽  
Optimal Conditions ◽  
Statistical Assessment ◽  
Free Data ◽  
Variable Nature ◽  
Wide Range ◽  
Research Aircraft ◽  
Using Data ◽  
Good Agreement

Abstract. We compare the performance of five hygrometers fitted to the Facility for Airborne Atmospheric Measurement's (FAAM) BAe 146-301 research aircraft using data from approximately one hundred flights executed over the course of two years under a wide range of conditions. Bulk comparison of cloud free data show good agreement between chilled mirror hygrometers and a WVSS-II fed from a modified Rosemount inlet but that a WVSS-II fed from the standard flush inlet appears to over read compared to the other instruments, except at higher humidities. Statistical assessment of hygrometer performance in cloudy conditions is problematic due to the variable nature of clouds, so a number of case studies are used instead to investigate the performance of the hygrometers in sub optimal conditions. It is found that the flush inlet is not susceptible to either liquid or solid water but that the Rosemount inlet has a significant susceptibility to liquid water; it is not susceptible to ice. In all conditions the WVSS-II respond much more rapidly than the chilled mirror devices, with the flush inlet-fed WVSS-II being more rapid than that connected to the Rosemount.

scholarly journals Onset of planet formation in the warm inner disk

2019 ◽  
Vol 629 ◽  
pp. A66 ◽  
Author(s):  
Tunahan Demirci ◽  
Corinna Krause ◽  
Jens Teiser ◽  
Gerhard Wurm
Keyword(s):  
Size Distribution ◽  
Room Temperature ◽  
Filling Factor ◽  
Planet Formation ◽  
Protoplanetary Disks ◽  
The Other ◽  
Sticking Probability ◽  
Wide Range ◽  
First Time ◽  
Wide Size Distribution

Aims. Collisional growth of dust occurs in all regions of protoplanetary disks with certain materials dominating between various condensation lines. The sticking properties of the prevalent dust species depend on the specific temperatures. The inner disk is the realm of silicates spanning a wide range of temperatures from room temperature up to sublimation beyond 1500 K. Methods. For the first time, we carried out laboratory collision experiments with hot levitated basalt dust aggregates of 1 mm in size. The aggregates are compact with a filling factor of 0.37 ± 0.06. The constituent grains have a wide size distribution that peaks at about 0.6 μm. Temperatures in the experiments are varied between approximately 600 and 1100 K. Results. Collisions are slow with velocities between 0.002 and 0.15 m s−1, i.e., relevant for protoplanetary disks. Aside from variations of the coefficients of restitution due to varying collision velocities, the experiments show low sticking probability below 900 K and an increasing sticking probability starting at 900 K. Conclusions. This implies that dust can grow to larger size in hot regions, which might change planet formation. One scenario is an enhanced probability for local planetesimal formation. Another scenario is a reduction of planetesimal formation as larger grains are more readily removed as a consequence of radial drift. However, the increased growth at high temperatures likely changes planetesimal formation one way or the other.

Sign in / Sign up

Export Citation Format

Share Document