Electron effective-mass values in GaxIn1−xSb alloys

1969 ◽  
Vol 47 (6) ◽  
pp. 631-636 ◽  
Author(s):  
Marcel J. Aubin ◽  
Mathew B. Thomas ◽  
Eric H. van Tongerloo ◽  
John C. Woolley
Keyword(s):  
Effective Mass ◽  
High Frequency ◽  
Room Temperature ◽  
Composition Range ◽  
Bridgman Technique ◽  
Scattering Parameter ◽  
Electron Effective Mass ◽  
High Frequency Dielectric Constant ◽  
The Matrix ◽  
Good Agreement

Room-temperature measurements of Faraday rotation, magneto–thermoelectric power, and infrared reflectance have been made on homogeneous coarsely polycrystalline n-type samples of GaxIn1−xSb alloys produced by the horizontal Bridgman technique. Using these data and a Kane equation for the (000) conduction band, values of the bottom of the band effective mass m00* have been determined over the composition range 0 < x < 0.85, i.e. the range in which the subsidiary [Formula: see text] minima make no contribution. The results from the three different techniques show very good agreement. From the data, values are obtained also for the square of the matrix element P2, the high-frequency dielectric constant ε∞, and the scattering parameter s for the various alloy specimens.

Dislocation structures around SiO2 Particles in aged Cu-Cr-SiO2

1978 ◽  
Vol 36 (1) ◽  
pp. 594-595
Author(s):  
N.J. Long ◽  
M.H. Loretto ◽  
C.H. Lloyd
Keyword(s):  
Flow Stress ◽  
Single Crystals ◽  
Room Temperature ◽  
Thin Foil ◽  
Age Hardening ◽  
Dispersion Strengthening ◽  
Accurate Picture ◽  
The Matrix ◽  
Very High ◽  
Good Agreement

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.

Electron effective mass values in GaAsxSb1−x alloys

1981 ◽  
Vol 59 (7) ◽  
pp. 939-944 ◽  
Author(s):  
Paul Devlin ◽  
Hassan M. Heravi ◽  
John C. Woolley
Keyword(s):  
Experimental Data ◽  
Effective Mass ◽  
Conduction Band ◽  
Faraday Rotation ◽  
Room Temperature ◽  
Electron Effective Mass ◽  
Kane Model ◽  
Experimental Variation ◽  
Infra Red ◽  
Best Fit

Measurements of Faraday rotation and of infra-red plasma reflectance have been made at room temperature on n-type polycrystalline samples of GaASxSb1−x alloys. Hence effective mass values m00* for the bottom of the (000) conduction band have been determined. The experimental variation of m00* with x is compared with the predictions of various models, viz., (a) a simple Kane model, (b) the model proposed by Berolo et al., and (c) the model proposed by Hermann and Weisbuch. It is found that the model of Berolo et al. gives the best fit to the experimental data.

Nernst–Ettingshausen Effects in GaxIn1–xAs alloys

1973 ◽  
Vol 51 (22) ◽  
pp. 2369-2375 ◽  
Author(s):  
Denis J. E. Demars ◽  
John C. Woolley
Keyword(s):  
Experimental Data ◽  
Magnetic Fields ◽  
Effective Mass ◽  
Room Temperature ◽  
Optical Scattering ◽  
Temperature Measurements ◽  
Scattering Coefficient ◽  
Alloy Sample ◽  
Alloy Scattering ◽  
Good Agreement

Room temperature measurements of longitudinal and transverse Nernst–Ettingshausen coefficients [Formula: see text] have been made on samples of GaxIn1–xAs alloys for a range of magnetic fields (B) up to 3.2 Wb/m2. Previous theoretical expressions for the values of these coefficients have been extended to the case of electrons in a single Kane band, and hence expressions for [Formula: see text] and [Formula: see text] obtained in terms of B, the bottom of the band effective mass m0*, and the scattering coefficient s. Fitting of these expressions to the experimental data thus has given values of m0* and s for each alloy sample. The values of m0* are found to be in good agreement with those obtained previously from plasma reflectance work, while the values of s indicate that over most of the alloy range polar optical scattering is predominant, but that in the range 0.4 < x < 0.7, alloy scattering may also have some contribution.

scholarly journals Electrostatically Tunable Nanomechanical Shallow Arches

2017 ◽  
Author(s):  
Syed N. R. Kazmi ◽  
Amal Z. Hajjaj ◽  
Pedro M. F. J. Costa ◽  
Mohammad I. Younis
Keyword(s):  
High Frequency ◽  
Room Temperature ◽  
Silicon On Insulator ◽  
Frequency Range ◽  
Shallow Arches ◽  
High Tunability ◽  
Band Pass ◽  
Dc Bias ◽  
Silicon Based ◽  
Good Agreement

We report an analytical and experimental study on the tunability of in-plane doubly-clamped nanomechanical arches under varied DC bias conditions at room temperature. For this purpose, silicon based shallow arches are fabricated using standard e-beam lithography and surface nanomachining of a highly conductive device layer on a silicon-on-insulator (SOI) wafer. The experimental results show good agreement with the analytical results with a maximum tunability of 108.14% for 180 nm thick arch with a transduction gap of 1 μm between the beam and the driving/sensing electrodes. The high tunability of shallow arches paves the ways for highly tunable band pass filtering applications in high frequency range.

Plasma Edge Reflectance Measurements in GaxIn(1−x)As and InAsxSb(1−x) Alloys

1971 ◽  
Vol 49 (15) ◽  
pp. 2052-2060 ◽  
Author(s):  
Mathew B. Thomas ◽  
John C. Woolley
Keyword(s):  
Experimental Data ◽  
Relaxation Time ◽  
Effective Mass ◽  
Conduction Band ◽  
Room Temperature ◽  
Plasma Edge ◽  
Electron Effective Mass ◽  
Reflectance Measurements ◽  
Type Conduction

Room temperature measurements of plasma reflectance have been made on polycrystalline homogeneous n type samples of GaxIn(1−x) As and InAsxSb(1−x) alloys. An analysis for the case of general degeneracy in a Kane-type conduction band has been developed, to allow the determination of electron effective mass (m0*/m) at the bottom of the conduction band. Hence values of m0*/m vs. x have been determined for both alloy systems. From the experimental data, values of relaxation time and optical mobility have also been calculated.

Ionization Energy and Electron Affinity of Clean and Oxidized AlxGa1−xN(0001) Surfaces

2001 ◽  
Vol 680 ◽  
Author(s):  
H. Nienhaus ◽  
M. Schneider ◽  
S.P. Grabowski ◽  
W. Mönch ◽  
R. Dimitrov ◽  
...  
Keyword(s):  
Electron Affinity ◽  
Ionization Energy ◽  
Room Temperature ◽  
Aluminum Content ◽  
Composition Range ◽  
Photoemission Spectroscopy ◽  
Negative Electron Affinity ◽  
Atom Flux ◽  
General Chemical ◽  
Good Agreement

ABSTRACTIonization energies and electron affinities of clean AlxGa1−xN(0001) surfaces were investigated by ultraviolet photoemission spectroscopy over the whole composition range. The samples were cleaned with cycles of N+-ion sputtering and annealing partly within a Ga atom flux. The ionization energy is measured as 6.5 eV and is almost independent of the aluminum content in good agreement with the general chemical trend. The electron affinity decreases linearly with composition from 3.1 eV for GaN to 0.25 eV for AlN. No evidence for negative electron affinity at AlN(0001) surfaces was found. Adsorption of oxygen at room temperature leads to a significant increase of the ionization energy and electron affinity. With AlN(0001) surfaces, an oxygen uptake of 0.6 monolayers is observed after exposures of 108 Langmuirs and the ionization energy increases by approximately 2 eV.

Transport Properties of n Type Cd3−xZnxAs2 Alloys

1975 ◽  
Vol 53 (14) ◽  
pp. 1333-1337 ◽  
Author(s):  
M. J. Aubin
Keyword(s):  
Matrix Element ◽  
Transport Properties ◽  
Room Temperature ◽  
Scattering Parameter ◽  
Type Analysis ◽  
The Matrix ◽  
Lattice Vacancies

Measurements of the Hall and magneto-Seebeck effects were performed on polycrystalline Cd3−xZnxAs2 alloys at room temperature. The range of x considered here (0 to 1) is characterized by samples which are normally n type. Analysis of the data with Kane's model gives a minimum of the matrix element P at x = 0.6 which is interpreted as the manifestation of the band crossover suggested by Wagner et at. The scattering parameter also exhibits a minimum but at x ~ 0.2. A possible explanation may involve the manner in which the zinc atoms occupy the lattice vacancies.

Theory of the Quasiparticle Effective Masses in Semiconductors based on an Electron Self Energy Approach

1990 ◽  
Vol 193 ◽  
Author(s):  
Xuejun Zhu ◽  
Mark S. Hybertsen ◽  
Steven G. Louie
Keyword(s):  
Effective Mass ◽  
Local Density ◽  
Energy Operator ◽  
Electron Interaction ◽  
Electron Effective Mass ◽  
Self Energy ◽  
Effective Masses ◽  
The Matrix ◽  
Energy Renormalization ◽  
Energy Dependent

ABSTRACTA conceptually complete formalism for the quasiparticle effective masses in semiconductors is proposed. Our approach is based. on a generalized form of the theory, including the effects of the nonlocal, energy dependent electron self: energy operator Σ, which accounts for the electron-electron interaction. This introduces two -important effects on the expression of the effective mass: an explicit energy renormalization and an extra contribution to the matrix element that enters the usual . Our preliminary numerical results for prototypical GaAs show promising improvements over the results from the local density approximation for the calculated electron effective mass compared to experimental data.

Impact modification of polyamide-12 through blending with liquid polybutadiene, 3 a Properties of compatibilized blends of PA12 and liquid polybutadiene

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Olivier Talon ◽  
Jean-Pierre Couvercelle ◽  
Claude Bunel
Keyword(s):  
Room Temperature ◽  
Composition Range ◽  
Melt Blending ◽  
Wide Composition Range ◽  
Polyamide 12 ◽  
The Matrix ◽  
Temperature Impact ◽  
Pyromellitic Anhydride ◽  
Impact Modification ◽  
Compatibilized Blends

Abstract Blends of polyamide 12 (PA12) and liquid polybutadiene (HTPB) compatibilized with pyromellitic anhydride (APy) were prepared by melt blending. 10%, 12% and 20% HTPB blends were prepared, with various amounts of APy. The influence of the amount of APy on the morphology of the blends was studied for a wide composition range in the 12% series. Injection moulded tensile and Charpy testing bars were prepared from 10% and 20% binary and compatibilized blends. The deformations of the matrix under room temperature impact and the morphology of the blends were investigated with scanning electron microscopy. Partial miscibilization of HTPB with PA12 due to the addition of APy was postulated to explain the disappearance of polybutadiene in some cases. The mechanical properties of the blends were correlated with morphological parameters. A strong correlation between impact fracture toughness and the amount of non-miscible HTPB was found.

Prediction of New Fingerprints of Ordering in GaInP2 Alloys

1995 ◽  
Vol 417 ◽  
Author(s):  
Alberto Franceschetti ◽  
Su-Huai Wei ◽  
Alex Zunger
Keyword(s):  
Band Gap ◽  
Effective Mass ◽  
Pressure Coefficient ◽  
Strong Anisotropy ◽  
Electron Effective Mass ◽  
Effective Masses ◽  
Epitaxial Strain ◽  
Degree Of Order ◽  
Good Agreement ◽  
Disordered Alloy

AbstractUsing ab initio all-electron methods, we investigate the evolution of effective masses, deformation potentials and pressure coefficients with the degree of long-range order in spontaneously ordered Ga0.5In0.5P alloys. We find that (i) the electron effective mass in the ordering direction increases significantly with the degree of order, while the effective mass in the perpendicular direction decreases; this produces a strong anisotropy of the electron effective mass which is not present in the disordered alloy; (ii) the band-gap deformation potential for (001) epitaxial strain decreases with increasing degree of order, reflecting the extent of the ordering-induced Γ - L coupling; (iii) the band-gap pressure coefficient decreases from 8.4 meV/kbar in the disordered alloy to 6.6 meV/kbar in the ordered CuPt structure; interpolation to partial degrees of order leads to good agreement with recent high-pressure experiments.

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