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1 Jul 1981

Volume 52, Issue 7, pp. 4363-4890

Page 2 of 4 Pages Previous Page Next Page | Jump to Page

Dynamics of magnetically stabilized laser discharge

C. E. Capjack, D. M. Antoniuk, and H. J. J. Seguin

J. Appl. Phys. 52, 4517 (1981); http://dx.doi.org/10.1063/1.329379 (6 pages) | Cited 17 times

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The dynamics of a rotating plasma in a transverse electrode geometry appropriate to high power CO2 laser discharge pumping is examined. The magneto‐gas‐dynamic fluid model used reveals that the spatially nonuniform electric and magnetic fields within the discharge cause the plasma and neutral gas rotational velocities to be strongly sheared within the cathode fall and the positive column regions. This sheared rotation serves to both stabilize the discharge against glow to arc transitions and to drive a centrifugal neutral gas flow within the volume. The concomitant bulk gas cooling effect so produced is particularly beneficial in a high powered CO2 electrical discharge laser as it inhibits thermal bottle necking. An order of magnitude increase in discharge power loading has been achieved utilizing a simple ’’magnetic electrode’’ discharge configuration.
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52.80.Hc Glow; corona
52.30.-q Plasma dynamics and flow
42.55.Lt Gas lasers including excimer and metal-vapor lasers

Constraints imposed upon theories of the vacuum arc cathode region by specific ion energy measurements

H. Craig Miller

J. Appl. Phys. 52, 4523 (1981); http://dx.doi.org/10.1063/1.329380 (8 pages) | Cited 28 times

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The presence of high‐energy ions (with potentials greater than the overall arc voltage) in the flux from the cathode region of vacuum arcs has been well established. While much excellent theoretical work has been done on the cathode region of a vacuum arc, only a modest amount of such work has predicted the energies of the ions leaving the cathode region. Two vacuum arc cathode theories which do predict the ion energies are the potential hump theory—where a positive space charge at the cathode spot accelerates the ions electrostatically, and the gas dynamic theory—where the ions are accelerated by a flow process. Few theorists have taken advantage of the available mass spectrometric data concerning individual ion energies. In this paper I compare such data with theoretical predictions. The best confirmed ion energy data is that for a copper cathode. Additional data are presented concerning the ion flux from a vacuum arc with a ten percent Bi/Cu cathode. Comparison of the copper and bismuth/copper data with the theoretical predictions shows that the potential hump and gas dynamic theories are in rough agreement with experiment, but are definitely not correct. Modifying the potential hump and gas dynamic theories by considering time‐dependent phenomena (i.e., incorporating nonequilibrium states into the theory) is shown to offer the promise of bringing either theory into better agreement with experiment. I conclude that the available data on the energies of the ions leaving the cathode region of a vacuum arc can serve as strong constraints on theoretical analyses.
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52.80.Vp Discharge in vacuum
52.80.Mg Arcs; sparks; lightning; atmospheric electricity

Breakdown and prebreakdown phenomena in liquids

John C. Devins, Stefan J. Rzad, and Robert J. Schwabe

J. Appl. Phys. 52, 4531 (1981); http://dx.doi.org/10.1063/1.329327 (15 pages) | Cited 65 times

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In this paper we present a comprehensive account of our results on streamer propagation in dielectric fluids in point‐plane geometries. Propagation velocities for both positive and negative streamers have been determined as a function of the following parameters: temperature, pressure, density, viscosity, composition, and conductivity. Effects of voltage and interelectrode spacing were examined. Current and light emission during streamer growth were measured. The relation between shock wave and streamer velocities was investigated. Small concentrations of low‐ionization potential additives markedly accelerated the positive streamers, while electron scavengers accelerated the negative streamers. Mechanisms to account for these observations are discussed.
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52.80.Wq Discharge in liquids and solids
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping

Surface‐potential decay in insulators with deep traps

M. Campos and J. A. Giacometti

J. Appl. Phys. 52, 4546 (1981); http://dx.doi.org/10.1063/1.329328 (7 pages) | Cited 10 times

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Surface‐potential decay characteristics of corona‐charged insulators are analyzed theoretically using a theory developed before by Rudenko. It was assumed that the charges are deposited in the surface of the insulator by a short corona pulse and that some amount of charge is instantaneously injected in the bulk of material. An analytical treatment of the standard transport equations in the presence of traps is presented. The model assumed for the traps is one in which they can be characterized by a single trapping time; liberation from traps was neglected, and also it was assumed that the traps are far from fully occupied. Using the theory it was possible to explain the fast decay of surface potential after a negative corona discharge in naphthalene single crystals. The value found for the trap‐modulated mobility at room temperature was 10−8cm2 V−1 s−1 and 110 s for the trapping time used as a parameter. With measurements of thermally stimulated currents, it was possible to find two sets of traps with activation energies of 0.6 and 1.2 eV.
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52.80.Hc Glow; corona
73.40.-c Electronic transport in interface structures
72.10.-d Theory of electronic transport; scattering mechanisms
73.90.+f Other topics in electronic structure and electrical properties of surfaces, interfaces, thin films, and low-dimensional structures (Restricted to new topics in section 73)

Transient response of a free‐burning discharge: Quantitative model

Jaroslav P. Novak, Magdi M. Shoucri, and Jean‐Nöel Séguin

J. Appl. Phys. 52, 4553 (1981); http://dx.doi.org/10.1063/1.329329 (8 pages) | Cited 7 times

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The work presented here deals with the application of the theoretical model of the nonequilibrium discharge developed by one of us to a free‐burning discharge in argon subjected to a current impulse. The paper includes a description of the system of transport equations and a discussion of the boundary conditions and numerical solutions. The response to a 0.5‐μs current ramp from 0.4 to 1.2 A is studied in detail. The variation of the basic parameters, such as the electron density, temperature, heat flux and diffusion velocity, the heavy‐particle temperature, and heat flux and the average mass velocity is shown as a function of time and space. Radial profiles of the initial and final states are shown to agree well with the results of the earlier steady‐state model.
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52.80.-s Electric discharges
51.50.+v Electrical properties (ionization, breakdown, electron and ion mobility, etc.)
52.25.Kn Thermodynamics of plasmas

Surface topography and alignment of liquid crystals on rubbed oxide surfaces

Minoru Nakamura

J. Appl. Phys. 52, 4561 (1981); http://dx.doi.org/10.1063/1.329330 (7 pages) | Cited 21 times

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For several nematic liquid crystals (LC’s), the relation between alignments of the LC’s on rubbed oxide surfaces and rubbing pressures of the substrates is given. When the LC’s take a parallel alignment to the surfaces, good homogeneous alignment is achieved at low pressures. High pressure rubbing also produces good homogeneous alignment of LC’s, although alignment is perpendicular to the nonrubbed surfaces. Fine stripes of deposited cloth fibers can be observed on the cloth‐rubbed oxide surfaces. The stripes consist of asymmetric projections ranging in the rubbed direction. On the basis of the asymmetric structure formed on the surface, the tilt direction of LC’s and their tilt angles are interpreted.
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61.30.Gd Orientational order of liquid crystals; electric and magnetic field effects on order
68.35.-p Solid surfaces and solid-solid interfaces: structure and energetics

Crystallographic polarity and chemical etching of CdxHg1−xTe

P. F. Fewster, S. Cole, A. F. W. Willoughby, and M. Brown

J. Appl. Phys. 52, 4568 (1981); http://dx.doi.org/10.1063/1.329331 (4 pages) | Cited 11 times

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The absolute crystallographic polarity of CdxHg1−xTe crystals (x?0.2) has been determined using the anomalous scattering of x rays and correlated with the chemical etching characteristics. It is shown that Cr Kα radiation adequately distinguishes 333 and 333 reflections, and that the reflected intensities agree closely with theoretical calculations. Using a range of chemical etchants it is reported that dislocation etch pits are revealed on the (111) or A face, i.e., the face terminating with triply bonded Cd (Hg) atoms or singly bonded Te atoms, and not on the (111) or B face.
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81.10.Aj Theory and models of crystal growth; physics and chemistry of crystal growth, crystal morphology, and orientation
61.50.-f Structure of bulk crystals
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)
68.35.-p Solid surfaces and solid-solid interfaces: structure and energetics

Evidence for 4f‐shell delocalization in praseodymium under pressure

H. K. Mao, R. M. Hazen, P. M. Bell, and J. Wittig

J. Appl. Phys. 52, 4572 (1981); http://dx.doi.org/10.1063/1.329332 (3 pages) | Cited 39 times

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Praseodymium metal undergoes a crystallographic phase transformation from a distorted fcc lattice to a distorted hcp structure at a pressure of ≃210 kbar. The phase change is accompanied by a large volume decrease of ≃19%. This decrease is analogous to the volume collapse at the γ‐α transition in cerium and thus provides strong evidence for a delocalization of the 4 f2 configuration into a 4f conduction band.
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61.66.Bi Elemental solids
64.70.K- Solid-solid transitions
71.20.-b Electron density of states and band structure of crystalline solids

Misfit dislocation‐free In1−xGaxAs1−yPy/InP heterostructure wafers grown by liquid phase epitaxy

Kazuo Nakajima, Susumu Yamazaki, Satoshi Komiya, and Kenzo Akita

J. Appl. Phys. 52, 4575 (1981); http://dx.doi.org/10.1063/1.329333 (8 pages) | Cited 21 times

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The conditions to grow misfit dislocation‐free In1−xGaxAs1−yPy/InP (0⩽x⩽0.47, 0⩽y⩽1.0) heterostructure wafers were first determined systematically by observing etch pits and x‐ray topographs. Etch pits were produced on InP substrates on which an In1−xGaxAs1−yPy layer was grown, and they were observed to find whether misfit dislocations generated or not. Threshold regions for initiation of misfit dislocations into the wafers were determined as a function of both lattice misfit and layer thickness. The misfit dislocation‐free regions determined by the etch pit observation of InP was found to be equivalent to the regions where misfit dislocations form in neither InP nor In1−xGaxAs1−yPy . The misfit dislocation‐free regions of the quaternary wafers are larger than the region of the ternary In1−xGaxAs/InP wafers by more than three times.
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61.72.Hh Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.)
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)

The influence of tin implantation on the oxidation of iron

I. J. R. Baumvol

J. Appl. Phys. 52, 4583 (1981); http://dx.doi.org/10.1063/1.329334 (6 pages) | Cited 8 times

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The high‐temperature oxidation of metallic iron implanted with Sn ions at doses between 5×1015 and 5×1016 Sn ions cm−2 is studied in the temperature range from 300 to 500 °C. Ion implantation of Sn reduces the oxidation rate constant of iron up to a factor of 10 at all experimental temperatures. The mechanisms that underlie this process are investigated using physical techniques such as Rutherford backscattering of  4He particles, conversion electron Mössbauer scattering of  57Fe and 119Sn and scanning electron microscopy to analyze the surface of the implanted and oxidized samples. The FeSn2 intermetallic phase was formed in the sample implanted at room temperature. This compound is partially decomposed to the FeSn intermetallic and free Sn in solution in iron when the implanted sample is oxidized at 500°C. Ion implantation produces a surface composition very similar to that obtained with the more conventional methods of tinplating. The observed inhibition of the corrosion is discussed on the basis of this similarity.
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61.72.U- Doping and impurity implantation
82.30.-b Specific chemical reactions; reaction mechanisms

Surface Mössbauer analysis of 38NCD4 steel ion implanted with nitrogen

M. Carbucicchio, L. Bardani, and S. Tosto

J. Appl. Phys. 52, 4589 (1981); http://dx.doi.org/10.1063/1.329335 (4 pages) | Cited 23 times

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Surface Mössbauer measurements have been carried out for 38NCD4 steel samples, ion implanted with nitrogen at different doses and currents. It has been found that Fe‐N compounds form in a wide range of compositions as aggregates in the steel matrix: from the unaffected base metal to the external surface, steel layers follow one upon the other in which first Fe2+yN with 0.3 ⩽ y < 2.7, then Fe2+xN with 0 ⩽x < 0.3, and finally austenite containing ∼10 at. % nitrogen, predominantly form. Dose decrease decreases the thickness of the above layers, while current variations produce differences in the relative amounts of the various Fe‐N compounds.
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61.72.U- Doping and impurity implantation
76.80.+y Mössbauer effect; other γ-ray spectroscopy
68.35.-p Solid surfaces and solid-solid interfaces: structure and energetics

Ion channeling and Auger electron spectroscopy study of Sb‐diffused Pb1−xSnxTe crystals

R. B. Alexander, W. E. Dorenbusch, and W. Lo

J. Appl. Phys. 52, 4593 (1981); http://dx.doi.org/10.1063/1.329336 (7 pages) | Cited 1 time

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An experimental study has been made of the effect of Sb diffusion on the crystalline quality and surface composition of Pb1−xSnxTe single crystals (x≊0.13) used in fabricating homojunction diode lasers. Both ion backscattering‐channeling and Auger electron spectroscopy have been employed. It is found that the crystalline quality in the bulk improves on diffusion, due to a decrease in dislocation density associated with the diffusion temperature. In the near‐surface region the quality deteriorates, due to the production of defects which are probably small clusters associated with Sb. The most pronounced effect is a partial or total loss of Te (and probably Sn) from the native oxide, accompanied by other changes in the oxide composition. A long term growth of a very thick oxide also occurs following diffusion. The changes in the oxide can be related to the formation of a p‐type surface layer on diffused crystals exposed to air, through oxygen adsorption.
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61.72.-y Defects and impurities in crystals; microstructure
66.30.J- Diffusion of impurities
61.85.+p Channeling phenomena (blocking, energy loss, etc.)
79.20.Fv Electron impact: Auger emission

Silver recoil yield resulting from krypton implantation

L. A. Christel and J. F. Gibbons

J. Appl. Phys. 52, 4600 (1981); http://dx.doi.org/10.1063/1.329337 (4 pages) | Cited 4 times

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The number of silver atoms which is recoil implanted into silicon during implantation of 255‐keV krypton is investigated as a function of silver film thickness and krypton dose using helium Rutherford backscattering. Results are in good agreement with calculations based on a Boltzmann transport equation approach. These calculations verify that the secondary and higher‐order recoils play a significant role in determining the total yield.
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61.72.U- Doping and impurity implantation
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces

Crystal perfection of HgI2 studied by neutron and gamma‐ray diffraction

W. B. Yelon, R. W. Alkire, M. M. Schieber, L. van den Berg, S. E. Rasmussen, H. Christensen, and J. R. Schneider

J. Appl. Phys. 52, 4604 (1981); http://dx.doi.org/10.1063/1.329338 (6 pages) | Cited 9 times

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The crystalline perfection of wire sawn pieces of vapor grown single crystals of mercuric iodide was compared with the perfection of (00l) cleaved sections of the same crystal from which nuclear radiation detectors have been fabricated. The crystalline perfection was studied using neutron and gamma‐ray diffraction rocking curves. Most of the gamma‐ray data were obtained using a high intensity source of 153Sm gamma rays with a wavelength of λ = 0.12 Å. Some of the data were obtained using highly penetrating 198Au gamma rays with a shorter wavelength of λ = 0.03 Å. The neutrons had a wavelength of λ = 1.07 Å. It was found that, in terms of the mosaic spread of the crystals, the cleaved detector plates have a much lower crystalline perfection than the thicker uncleaved detector plates. At the same time, the results show that for detectors cut from the same crystal, the one with the lower spectral resolution for radiation detection will also have a lower perfection and larger width of the gamma‐ray rocking curve. These results suggest consideration should be given to alternative fabrication procedures for HgI2 nuclear radiation detectors.
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61.72.Lk Linear defects: dislocations, disclinations
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
61.05.C- X-ray diffraction and scattering

Theoretical account for the response of manganin gauges

Y. Partom, D. Yaziv, and Z. Rozenberg

J. Appl. Phys. 52, 4610 (1981); http://dx.doi.org/10.1063/1.329339 (7 pages) | Cited 13 times

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We propose a theoretical model to account for the dynamic response of manganin gauges in plane impact experiments. It is based on the concept that the elastoplastic behavior of a polycrystalline material depends significantly on the fact that it is made up of single‐crystal grains randomly oriented in space. We refer to this approach as the grains model. By adjusting a single mechanical parameter and three piezoresistance parameters, contained in our model, we are able to reproduce the available experimental calibration curves for manganin.
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62.20.F- Deformation and plasticity
62.50.-p High-pressure effects in solids and liquids

Diffusion of zinc in gallium arsenide: A new model

U. Gösele and F. Morehead

J. Appl. Phys. 52, 4617 (1981); http://dx.doi.org/10.1063/1.329340 (3 pages) | Cited 156 times

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Experimental results on the diffusion of Zn in GaAs which could not be satisfactorily explained in terms of a Frank–Turnbull mechanism involving vacancies can be understood with a ’’kick‐out model’’ in which the equilibrium between interstitial and substitutional Zn is established via gallium interstitials.
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66.30.J- Diffusion of impurities
66.30.Lw Diffusion of other defects

Effect of oxygen on the diffusion of Al in Pt films

Chin‐An Chang

J. Appl. Phys. 52, 4620 (1981); http://dx.doi.org/10.1063/1.329341 (3 pages) | Cited 15 times

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Diffusion of Al in Pt films over the temperature range of 200°–600 °C has been studied in different ambients. A single phase of Pt5Al3 is observed in forming gas at 200 °C, which starts to transform into Pt3Al above 400 °C. In the presence of oxygen, however, the formation of Pt5Al3 is completely suppressed at 200 °C and greatly reduced at 300 °C. It also slows down the transformation into Pt3Al at higher temperatures. These are in agreement with the predicted effect of oxygen on the diffusion of Al in Pt films.
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66.30.-h Diffusion in solids
68.35.-p Solid surfaces and solid-solid interfaces: structure and energetics
81.05.Bx Metals, semimetals, and alloys
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

The surface energy of Si, GaAs, and GaP

C. Messmer and J. C. Bilello

J. Appl. Phys. 52, 4623 (1981); http://dx.doi.org/10.1063/1.329342 (7 pages) | Cited 69 times

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The surface energy of various planes in Si, GaAs, and GaP was measured by the use of a modified spark discharge method, previously used successfully in metals. Surface energy values were determined for the following cleavage planes in these crystals: Si {111}∼1.14 J/m2, Si {110}∼1.9 J/m2, GaAs {110}∼0.86 J/m2, and GaP {110}∼1.9 J/m2. The Si surface energy value was compared with previous experimental measurements. The Si {110}, GaAs {110}, and GaP {110} values were compared only to theoretical estimations, since as far as it is known, the surface energy of these planes have never been measured experimentally. Berg‐Barrett x‐ray topography and chemical etch pit analysis verified that plastic relaxation did not occur under the test conditions used. The cleavage surface energies determined in this work were in good agreement with previous theoretical estimations. Experimental observations confirmed a lack of plastic energy dissipation and a stability of cleavage propagation which indicated that the measured surface energies were close to the intrinsic values.
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68.35.Md Surface thermodynamics, surface energies
62.20.M- Structural failure of materials

Hillock‐free integrated‐circuit metallizations by Al/Al‐O layering

T. J. Faith

J. Appl. Phys. 52, 4630 (1981); http://dx.doi.org/10.1063/1.329343 (10 pages) | Cited 15 times

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Hillocks which grow on aluminum integrated‐circuit films during the contact alloying process present processing and reliablity problems. Layered Al/Al‐O films, deposited by periodically introducing controlled amounts of oxygen into the aluminum‐deposition chamber, are shown to provide dramatic improvements in post‐anneal film‐surface topography. Aluminum films, unlayered Al‐O films, and layered Al/Al‐O films were deposited on thermally‐oxidized silicon wafers in an e‐beam system to thicknesses of approximately 1 μm at a rate of 25 Å/s. The films were photolithographically patterned into arrays of 100×100‐μm bond pads and 7‐μm lines, and annealed in forming gas for 20 min at 530 °C. After these anneals, both aluminum films and unlayered Al‐O films with oxygen concentrations less than approximately 6 at.% had surface protrusions (hillocks and/or whiskers) approximately 1 μm in height. Protrusion density was on the order of 105 cm−2. Al‐O films with oxygen concentrations greater than 6 at.% displayed blistering and had resistivities greater than twice those of aluminum films. Layered Al/Al‐O films with a structure consisting of four layers of 1000‐Å Al/1000‐Å Al‐O topped with 2000 Å of Al had no protrusions with heights greater than 0.5 μm for oxygen concentrations in Al‐O layers ranging from 1.5 to 6 at. %. Overall composite‐film resistivities ranged from approximately 15–45% higher than aluminum films over this oxygen‐concentration range. Both film surface roughness and the density of hillocks with heights less than 0.5 μm decreased with increasing oxygen concentrations. The thickness of the top Al layer was an important layering parameter; 1‐μm hillocks appearing on bond pads of films with top Al layers either less than approximately 1500 Å or greater than approximately 3000 Å thick. However, the 7‐μm lines were hillock free even for such non‐optimum layering structures. Al/Al‐O layering also yielded dramatic improvement in post‐530 °C‐anneal topography for films deposited at 4 Å/s in an S‐Gun® magnetron sputtering system. The S‐Gun layered films had a generally higher density of short ( ⩽ 0.5 μm) hillocks than the e‐beam layered films.
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68.55.-a Thin film structure and morphology
61.90.+d Other topics in structure of solids and liquids; crystallography (restricted to new topics in section 61)
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
81.40.-z Treatment of materials and its effects on microstructure, nanostructure, and properties

Liquid phase epitaxy of high‐purity GaAs on conducting n‐type substrates

J. R. Shealy

J. Appl. Phys. 52, 4640 (1981); http://dx.doi.org/10.1063/1.329344 (6 pages) | Cited 2 times

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The liquid phase epitaxial technique for the deposition of lightly doped n‐type GaAs on conducting n‐type substrates is described. The effect of the starting materials, in particular the substrates and the undoped source crystal, on the epitaxial layer properties has been observed for a fixed set of growth conditions. Schottky barriers fabricated on this material exhibit near ideal current‐voltage characteristics with breakdown voltages approaching the theoretical limit.
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68.55.-a Thin film structure and morphology
81.10.Dn Growth from solutions
73.61.Cw Elemental semiconductors
73.61.Ey III-V semiconductors
73.61.Ga II-VI semiconductors
73.61.Jc Amorphous semiconductors; glasses
73.61.Le Other inorganic semiconductors

Effective masses for nonparabolic bands in p‐type silicon

Frank L. Madarasz, Joseph E. Lang, and Patrick M. Hemeger

J. Appl. Phys. 52, 4646 (1981); http://dx.doi.org/10.1063/1.329345 (3 pages) | Cited 45 times

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The nonparabolic nature of the valence bands of silicon gives rise to an explicit temperature dependence in the density of states effective mass as defined through the carrier concentration as well as an energy dependence in the mass defined through the density of states itself. Both masses are important to those researchers interested in fitting electronic transport data. In the past the temperature dependent effective mass of Barber has been most commonly used. The approximations that have gone into the Barber mass are somewhat oversimplified in that he only approximated the actual band structure. We present a more complete calculation, and compare it with the results of Barber for nondegenerate p‐type silicon. There is a significant difference, a factor of about 1.4, between our results and his in the temperature range 300–600 K. The difference is quite noticeable in calculating electronic transport quantities such as carrier concentration or conductivity mobility.
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71.20.-b Electron density of states and band structure of crystalline solids
71.18.+y Fermi surface: calculations and measurements; effective mass, g factor
72.20.-i Conductivity phenomena in semiconductors and insulators
72.80.Cw Elemental semiconductors

The electrical properties of sulphur in silicon

S. D. Brotherton, M. J. King, and G. J. Parker

J. Appl. Phys. 52, 4649 (1981); http://dx.doi.org/10.1063/1.329346 (10 pages) | Cited 45 times

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Hall effect and diode C‐V type measurements (including DLTS) have been used to study the several levels introduced by sulphur into the upper half of the silicon band gap. Where possible, the electron capture cross section of each level has also been measured. The results are interpreted in terms of two well characterized and reproducibly occurring centers sulphur I (0.18 and 0.38 eV) and sulphur II (0.32 and 0.53 eV). A third center, or variety of close centers, with energy levels of <0.1 eV were also found, but their occurrence was determined by the starting material and diffusion conditions. The centers sulphur I and II were both assumed to be double donors.The observed variations in concentration of sulphur I and sulphur II with diffusion temperature have enabled us to fit previously published results into a consistent pattern.
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78.40.Fy Semiconductors
72.20.Fr Low-field transport and mobility; piezoresistance
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
72.80.Cw Elemental semiconductors

Analysis of symmetrical Hall plates with finite contacts

W. Versnel

J. Appl. Phys. 52, 4659 (1981); http://dx.doi.org/10.1063/1.329347 (8 pages) | Cited 18 times

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Hall plates with four equal edge contacts of nonzero lengths, which are invariant for a rotation through 90°, are considered. Analytical formulas for Hall voltage and the Hall mobility, in which the finiteness of the contacts and the magnetic field are taken into account, have been obtained. The numerical calculations involved can be reduced to those of regular integrals. In addition, for a number of symmetrical shapes of Hall plates simple approximations have been derived for the product μB of Hall mobility and magnetic induction. The maximum length is calculated of each contact, for which these approximations are accurate to within 0.5% compared to exact solutions. Numerical data are tabulated in a directly applicable form.
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72.15.Gd Galvanomagnetic and other magnetotransport effects
72.20.My Galvanomagnetic and other magnetotransport effects
84.32.Dd Connectors, relays, and switches

Brillouin instability in longitudinally magnetized n‐type piezoelectric semiconductors

S. Ghosh

J. Appl. Phys. 52, 4667 (1981); http://dx.doi.org/10.1063/1.329348 (5 pages) | Cited 8 times

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Stimulated Brillouin scattering of a plane polarized intense electromagentic wave propagating parallel to the applied magnetic field has been investigated analytically in an n‐type piezoelectric semiconductor plasma. The general dispersion relation has been obtained and solved for both the cases of scattered electromagnetic waves (i.e., in the cases of left‐hand and right‐hand circularly polarized waves) to study the threshold condition and the growth rate of the unstable Brillouin mode at a pump amplitude well above the threshold. The relevant experiment has not been reported. Numerical estimates have been made for n‐type InSb at 77 K irradiated with a pulsed 10.6‐μm CO2 laser to obtain the necessary electric field. The threshold electric field is independent of applied magnetic field, and the growth rate of the unstable Brillouin mode has linear dependence on the magnetic field.
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72.20.Ht High-field and nonlinear effects
72.30.+q High-frequency effects; plasma effects
77.65.-j Piezoelectricity and electromechanical effects

Beryllium doping in Ga0.47In0.53As and Al0.48In0.52As grown by molecular‐beam epitaxy

K. Y. Cheng, A. Y. Cho, and W. A. Bonner

J. Appl. Phys. 52, 4672 (1981); http://dx.doi.org/10.1063/1.329349 (4 pages) | Cited 12 times

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Beryllium‐doped Ga0.47In0.53As and Al0.48In0.52As epitaxial layers lattice matched to InP substrates have been grown by molecular‐beam epitaxy (MBE). Doping levels as high as 2.5×1019 cm−3 have been achieved for both p‐type Ga0.47In0.53As and Al0.48In0.52As. The maximum carrier concentration is an order of magnitude higher for these Be‐doped layers than for those doped with Mn. The carrier concentration varies proportionally with the arrival rate of Be and the sticking coefficient of Be is estimated to be unity. Under our growth conditions, the carrier concentrations in Ga0.47In0.53As and Al0.48In0.52As layers are identical for the same Be arrival rate. Mobility studies showed that MBE grown Be‐doped Ga0.47In0.53As layers are comparable to the best reported results obtained with liquid‐phase epitaxy. When Sn was used as the n‐type dopant, both Ga0.47In0.53As and Al0.48In0.52As p‐n junction diodes were fabricated and evaluated.
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72.20.Fr Low-field transport and mobility; piezoresistance
73.61.Cw Elemental semiconductors
73.61.Ey III-V semiconductors
73.61.Ga II-VI semiconductors
73.61.Jc Amorphous semiconductors; glasses
73.61.Le Other inorganic semiconductors
72.80.Ey III-V and II-VI semiconductors
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
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