bluuebunny/crossref_metadata_2025 huggingface dataset:
cw HF ELECTRIC-DISCHARGE MIXING LASER
Authors: Hinchen J. J. , Banas C. M.
Published: January 2004

Continuous chemical laser operation was observed with HF and DF in a system in which fluorine atoms produced in a glow discharge in SF6 are mixed with hydrogen in a subsonic flow region upstream of a transverse optical cavity. A maximum power output of 5.5 W was obtained and measurements of the output spectral distribution were made.
HIGH-POWER CO2 ELECTRIC DISCHARGE MIXING LASER
Authors: Brown Clyde O.
Published: January 2004

An electric discharge mixing laser is described in which N2 is vibrationally excited in an electrical discharge and then mixed with cold CO2 providing a population inversion and, consequently, lasing action at 10.6μ in a high-pressure high-flow speed channel. Convection is the principle heat removal mechanism, permitting system operation at power densities substantially higher than in conventional wall-dominated electric discharge lasers. Results of experiments with a 30-cm-wide by 1.2-cm-high EDML channel are described. With this system, small-signal gain coefficients of 4.3% cm−1 and optical powers of up to 900 W at 11% efficiency have been obtained at a pressure of 48 Torr.
ENHANCED DIFFUSION OF HIGH-TEMPERATURE ION-IMPLANTED ANTIMONY INTO SILICON
Authors: Gamo Kenji , Masuda Kohzoh , Namba Susumu , Ishihara Shinji , Kimura Itsuro
Published: January 2004

Concentration profiles of 20-keV high-temperature ion-implanted antimony into a silicon single crystal were measured by means of radioactivation analysis and the enhanced diffusion was observed. The concentration profiles were found to be independent of temperature over the range between 500 °C and 800 °C and to be dependent on the dose rate of ion implantation. The diffusion coefficient of antimony is estimated to be about 1.1×10−15 cm2/sec for the dose rate of about 1.2×1012 ions/cm2 sec and about 6.6×10−15 cm2/sec for that of about 7.2×1012 ions/cm2 sec. The measured concentration profiles are in good agreement with the calculated concentration profile. These results are explained on the basis of a vacancy mechanism.
Nd,Cr : YAlO3 LASER TAILORED FOR HIGH-ENERGY Q-SWITCHED OPERATION
Authors: Bass M. , Weber M. J.
Published: January 2004

Spectral and pulsed laser properties of Nd3+ : YAlO3 crystals codopes with Cr3+ are described. The anisotropic properties of yttrium orthoaluminate were used to select a laser rod orientation which maximized the energy storage capability for Q-switched operation. It is demonstrated that a c-axis rod of this material can produce energy outputs greater than those obtainable from the best Nd3+ : YAG rods of comparable size in both long-pulse and Q-switched laser operation.
CHARACTERIZATION OF SILICON SURFACES BY THE ELECTRON ENERGY-LOSS SPECTRUM
Authors: Wei P. S. P.
Published: January 2004

The energy-loss spectra of silicon during several stages of the cleaning treatment have been studied in a LEED apparatus. The results suggest that the energy-loss spectrum is sensitive to the change in chemical composition and electronic structure of the solid surface.
HIGH-ORDER TRANSVERSE CAVITY MODES IN HETEROJUNCTION DIODE LASERS
Authors: Butler J. K. , Sommers H. S. , Kressel H.
Published: January 2004

A refined theoretical model predicts the modal content in the plane perpendicular to the junction for heterojunction injection lasers. It gives good agreement with observed far-field patterns. Because high-order modes are favored, lasers with a wide optical cavity sandwiched between two heterojunctions have a beam width at least double that of single-heterojunction lasers. In a thin cavity which supports but one mode, the increased confinement of the double heterojunction broadens the beam to about 40° at half-power.
EFFECTIVE MASS CHANGE OF ELECTRONS IN SILICON INVERSION LAYERS OBSERVED BY PIEZORESISTANCE
Authors: Dorda G.
Published: January 2004

Piezoresistance coefficients were determined for n-type inversion layers at low gate fields on (100), (110), and (111) surfaces of silicon at room temperature. Results deviating from bulk values were found on the (110) and (111) planes. This anomaly can be understood in terms of changed effective masses of conduction electrons on the surface as a consequence of the quantization of the carrier wave function in the surface channel. Good agreement between theoretical results and experiment was found. It was observed that the quantization is efficient even at the threshold voltage (i.e., ∼2×104 V/cm) and occasions the anisotropic piezoresistance on the (110) surface.
THERMOELASTIC DOSIMETRY OF RELATIVISTIC ELECTRON BEAMS
Authors: Perry F. C.
Published: January 2004

A technique is described of obtaining directly the energy absorption profile of a solid heated by pulses of intense radiation. The appropriate thermoelastic equations were solved for two cases of particular interest, instantaneous deposition and energy absorbed at a constant rate. The dynamic response of aluminum and copper to electrons of everage energy 1.5 MeV was measured by means of a laser interferometer, and the resulting energy profiles were compared with profiles obtained using a thin film dosimetry technique. The resulting quantitative agreement with the thermoelastic theory is discussed.
Chain-Reaction Chemical Laser Using H2–F2–He Mixtures
Authors: Hess LaVerne D.
Published: January 2004

Laser action was observed from HF produced in a chain reaction between H2 and F2 initiated by flash photolysis of H2–F2–He mixtures. Conditions were found for mixing the reagents at room temperature without the occurrence of spontaneous ignition.
Lattice Disorder in Ion-Implanted Boron-Doped Silicon
Authors: Hirvonen J. K. , Eisen F. H.
Published: January 2004

The lattice disorder produced in 40–600-keV heavy ions implanted in undoped and heavily boron-doped silicon has been measured using the channeling technique. The lattice disorder shows no significant dependence on the boron concentration of the implanted silicon for the variety of heavy ion species, doses, and implantation temperatures used.
Miniature Ultrasensitive Superconducting Magnetic Gradiometer and Its Use in Cardiography and Other Applications
Authors: Zimmerman J. E. , Frederick N. V.
Published: January 2004

A portable magnetic gradiometer was built using an rf-biased point contact device as a sensor and a superconducting flux transformer 2.5 cm in diameter by 10 cm long to couple to the gradient of the external field. The instrument is limited by fluctuations which are probably associated with an uneven boiling of the cryogenic liquids and by environmental fluctuations in some locations. It is shown that the inherent sensitivity can be increased by an order of magnitude by increasing the bias frequency from 30 to 300 MHz. A possible use of the instrument as a magnetocardiograph in an unshielded environment was demonstrated.
Infrared Sidelight Studies in the High-Power Carbon Monoxide Laser
Authors: Rich J. William , Thompson Herbert M.
Published: January 2004

Spontaneous radiation on the CO fundamental vibration-rotation bands, created by sidelight emission from a liquid-nitrogen—cooled CO–He laser, has been studied spectroscopically. The CO rotational temperature and the relative populations of vibrational states v=1 to v=14 have been inferred. The vibrational population distribution is significantly non-Boltzmann.
Stimulated Emission and Laser Action in Gallium Nitride
Authors: Dingle R. , Shaklee K. L. , Leheny R. F. , Zetterstrom R. B.
Published: January 2004

Stimulated emission and laser action have been observed near 3.45 eV in single-crystal needles of GaN. These observations support the earlier suggestion that GaN is a direct band-gap semiconductor with Eg∼3.50 eV at 2°K. Furthermore, the occurrence of very high gain (g∼105 cm−1) in the stimulated emission emphasizes the possible device potential of this material.
Current Dependency of the Conducting Channel Diameter in Thin-Film Glass Switches
Authors: Schuöcker D.
Published: January 2004

Measurements showed that a fast rising square-wave current pulse imposed on a thin-film As–Te–Gi–Si glass switch in the on-state causes a fast voltage rise followed by a much slower decrease. This is explained with the expansion of the conducting channel: This motion cannot follow immediately the fast rise of the current and thus the current density and the related voltage rise. During the following expansion, both quantities decrease again. The measured positive differential resistance of the on-state is referred to the current constrictions in the electrodes, caused by the small channel diameter.
High-Resolution Measurements of Electron Energy Distribution Peak Shifts
Authors: Tracy J. C. , Rowe J. E.
Published: January 2004

A method to measure peak shifts in electron energy distributions to resolutions several orders of magnitude smaller than the peak widths is described. It is a continuous measurement applicable to any analyzer capable of using the ac method of derivative detection. Its application to the temperature dependence of the position of the ``d-band'' peak in uv photoemission from Ni shows that it is capable of detecting 1-meV peak shifts in this case.
Doped Triglycine Sulfate for Pyroelectric Applications
Authors: Lock P. J.
Published: January 2004

Crystals of triglycine sulfate (TGS) grown from solutions containing alanine are found to give biased ferroelectric hysteresis loops. The material is therefore always in a fully poled state when below its Curie point in the absence of large external fields. The values of ε′ and ε″ are lower than for pure TGS. Pyroelectric infrared detectors using this material approach within an order of magnitude of the limit of sensitivity for uncooled thermal detectors.
Deformation of Nematic Liquid Crystals with Vertical Orientation in Electrical Fields
Authors: Schiekel M. F. , Fahrenschon K.
Published: January 2004

A new electro-optical effect in nematic liquid crystals with negative dielectric anisotropy is described, using sandwich cells with molecular orientation perpendicular to the electrode surface (homeotropic alignment). In an arrangement between crossed polarizers, high-contrast ratios have been achieved with low voltages. This effect shows a high degree of non-linearity and thus permits the development of matrix displays without using additional non-linear elements.
Red Photoluminescent Efficiency and Minority-Carrier Lifetime of GaP(Zn,O) Pulled from Nonstoichiometric Melts
Authors: Jordan A. S. , Von Neida A. R. , Caruso R. , DiDomenico M.
Published: January 2004

GaP (Zn, O) crystals pulled from nonstoichiometric melts by the liquid-encapsulation Czochralski (LEC) technique bridge the gap between the red photoluminescent quantum efficiencies of platelets grown from solution and crystals pulled by LEC from a stoichiometric melt. A linear correlation is shown to exist between the nonradiative shunt-path component of the total reciprocal minority-carrier lifetime and the Ga-vacancy concentration of these different crystals.
Tunable Spin-Flip Raman Laser at Magnetic Field as Low as 400 G
Authors: Patel C. K. N.
Published: January 2004

We report the first operation of a tunable cw spin-flip Raman laser at magnetic fields as low as 400 G. We also report the first observation of a tunable cw anti-Stokes spin-flip Raman (SFR) laser. These results should allow the SFR lasers to be operated with small electromagnets rather than the superconducting solenoids used heretofore.
Current Transport, Effective Dielectric Constant, and Temperature of Ta2 O5 Thin Films
Authors: O'Clock George D.
Published: January 2004

The I-V characteristics of Ta–Ta2O5–Au thin-film devices indicate high temperatures and large dielectric constants for both Schottky and Poole-Frenkel dominated conduction. The effects of space charge and electron effective mass are also indicated.
Amphoterically Silicon-Doped Gallium Arsenide Laser
Authors: Ahn B. H. , Trussell C. W. , Shurtz R. R.
Published: January 2004

A successful attempt has been made in fabricating an amphoterically silicon-doped gallium arsenide laser which operates at room temperature. Silicon doped n and p layers were grown in one step using the liquid phase epitaxy method. The threshold current densities were 3400 and 58 700 A/cm2 at 77 and 300 °K, respectively. The best beam divergence observed was 11 ° at the half-power point. The heavily compensated p layer and long electron-diffusion length were overcome by use of a potential barrier.
Bistable Electrical Switching in Polymer Thin Films
Authors: Carchano H. , Lacoste R. , Segui Y.
Published: January 2004

Reproducible bistable switching has been observed in Au-Polymer-Au junctions. The polymer is formed by a glow-discharge polymerization technique. The resistance ratio is more than 107 and structures can be switched more than 2000 times. When the polymer thickness is lower than 1500 Å, the threshold voltage increases linearly with the polymer thickness. A scanning electron microscope picture of a junction that has been switched shows circular dots, ranging between 5- and 10- μm diameter, on the surface. These dots are probably due to current-carrying filaments.
Optical Filament Formation in Nitrobenzene Resulting from Laser Intensity Inhomogeneities
Authors: Abbi Satish C. , Mahr Herbert
Published: January 2004

An experiment was performed in nitrobenzene with a multimode ruby laser to study filament formation as a function of beam aperture size. A theory which assumes that optimum-size intensity spikes of the incident-laser-beam self-focus first can explain the experimental results with one adjustable parameter.
Thermal Effects in Amorphous-Semiconductor Switching
Authors: Kaplan Theodore , Adler David
Published: January 2004

It is shown that a pure thermal model, in the absence of significant heating of the electrodes, gives no negative differential resistance and no high-current filaments. When some electronic effects, such as space charge, narrow Schottky barriers, or field-enhanced conductivity, are explicitly introduced, negative-resistance regions and filamentary conduction exists.
Optical Guided Wave Mode Conversion by an Acoustic Surface Wave
Authors: Kuhn L. , Heidrich P. F. , Lean E. G.
Published: January 2004

The experimental observation of efficient (55%) mode conversion of thin-film optical guided waves by a collinear interaction with a surface acoustic wave is reported. The effects of waveguide dispersion and finite geometry are discussed.
Intracavity Radiation-Induced Air Breakdown in a TEA CO2 Laser
Authors: Tulip J. , Manes K. , Seguin H. J.
Published: January 2004

Radiation-induced air breakdown has been produced within the cavity of a TEA CO2 laser using an intracavity lens arrangement. Results indicate that this technique could be used for effective plasma heating because it permits fast energy dumping into low-pressure sparks.
Epitaxial (CdHg)Te Infrared Photovoltaic Detectors
Authors: Cohen-Solal G. , Riant Y.
Published: January 2004

Fast sensitive photovoltaic detectors operating in the 77–130°K temperature range are prepared from (CdHg)Te epitaxial layers. Junction-formation technique involves deviations from stoichiometry. The spectral response per quantum at 77°K is flat over a wide wavelength range (3–14 μm). Detectivity measurements in this wavelength range yield values at 77 °K between 3×109 and 3×1010 cm Hz1/2W−1. External quantum efficiency is around 13%. The time constant of these detectors is less than 1 nsec.
Stabilization of Sausage Instability in Semiconductor Plasma by Axial Magnetic Field
Authors: Tacano Munecazu , Kataoka Shoei
Published: January 2004

Stabilization of pinch oscillations in an avalanching n-InSb by an axial magnetic field is experimentally studied in detail, and reasonable agreement is obtained with theoretical considerations based on a model of sausage instability in the adiabatically compressed linear pinch.
Reply to ``Comments on Formation of Vacancy Condensation Pits on the Surface of Metals on Quench Annealing''
Authors: Tariyal B. K. , Ramaswami B.
Published: January 2004

In their comments on our paper, Wyon et al. have suggested that in our experiments pits form during quenching, which is equivalent to slow cooling. A repetition of the quenching experiments and analysis of the results suggests that pits could not have formed during the quench. The differences between our observations and those of Wyon et al. are discussed on the basis of the existing theory of pit formation and the different rates of cooling.
Simplified Low-Noise He–Cd Laser with Segmented Bore
Authors: Silfvast W. T. , Szeto L. H.
Published: January 2004

A simplified He–Cd laser using a segmented-bore design has produced 10 mW at 4416 Å and 2.5 mW at 3250 Å in a 2-mm-bore 26-cm-length discharge using naturally occurring Cd. A low-noise output can be obtained at a slight sacrifice in peak power.
Raman Scattering Cross Section for N2O4
Authors: Chen Che Jen , Wu Frank
Published: January 2004

The Raman scattering cross section for N2O4 at a Raman shift of 1360 cm−1 is measured by using a Q-switched ruby laser as an excitation source. The cross section for N2 at a Raman shift of 2330 cm−1 has also been measured and is compared with a previous measurement.
Thermally Restorable Optical Degradation Effects in Heat-Treated Cu2S–CdS Crystal Heterojunctions
Authors: Kanev Stefan K. , Fahrenbruch Alan L. , Bube Richard H.
Published: January 2004

We have shown that heat treatment alone does not produce appreciable degradation of the short-circuit current in Cu2S–CdS single-crystal photovoltaic heterojunctions. The degradation, which has been commonly observed, is the result of optically induced effects in the heat-treated cell, subsequent to the heat treatment. These optically induced effects can be correlated with photochemical changes induced in single crystals of CdS: Cd: Cu in which the density of Cu acceptors exceeds the density of excess-Cd donors. Major conclusions about the mechanism of the photovoltaic effect and heat-treatment processes can be drawn.
Behavior of High-Purity Germanium Nuclear Counters at Low Temperature
Authors: Stuck R. , Ponpon J. P. , Siffert P. , Ricaud C.
Published: January 2004

γ-ray spectrometers prepared from high-purity germanium have been operated at low temperatures down to 5°K. The energy resolution of completely depleted detectors was the same at 5°K as at 77°K and no trapping-detrapping phenomena were observed. However, at sufficiently low bias voltage, slow components appeared on the pulses below 8°K. This effect is shown to be related to the increase in the resistivity of the undepleted region.
Growth-Induced Noncubic Anisotropy Arising from the Tetrahedral Sites in Garnets
Authors: Akselrad Aline , Callen Herbert
Published: January 2004

We have observed noncubic growth-induced anisotropy in garnets prepared to preclude the mechanism based on rare-earth ions, such as Eu3Fe5−xGaxO12 with a single rare-earth ion, or such as Y3−2xCa2xVxFe5−x O12 with only diamagnetic ions on the dodecahedral sites; all samples contain a mixture of constituents on tetrahedral sites. We show that the noncubic anisotropy can be explained by distortion of the local symmetry around tetrahedral ions caused by preferential site ordering among their tetrahedral neighbors. A similar distortion of tetrahedral symmetry by ordering of dodecahedral ions should contribute in mixed rare-earth garnets.
New Method for Breakdown Voltage Determination in p-n Junctions
Authors: Oldham W. G. , Antognetti P. , Samuelson R. R.
Published: January 2004

The triggering behavior of small-area uniform avalanche diodes may be used to measure the breakdown voltage. The diode is biased at sufficiently high reverse voltage that pulses of current appear and the relative probability of a generated electron or hole triggering an avalanche is determined by measuring the pulse rate. Performing the measurements over a range of bias and extrapolating the pulse rate to zero yield the breakdown voltage to within a few millivolts.
Growth of Periodic Structures by the Molecular-Beam Method
Authors: Cho A. Y.
Published: January 2004

Molecular-beam epitaxy has been used successfully for the attainment of single-crystal multiple-layer structures with alternating types of conductivities (p/n) or band-gap energies (GaAs/AlxGa1−xAs). Deposition by the molecular-beam method offers the possibility of growing periodic-structure layers with constant chemical composition profiles and controlled uniform thicknesses.
Direct-Current Electroluminescence in Rare-Earth-Activated Zinc Sulphide Powder Layers
Authors: Waite M. S. , Vecht A.
Published: January 2004

Narrow-band luminescence from rare-earth centers in zinc sulphide powders has been observed with medium-voltage direct-current excitation for five rare-earth-doped zinc sulphide phosphors. The brightness and powder efficiencies have been measured and the electroluminescent spectra obtained show differences from the photoluminescent spectra.
Electromigration in Al Films Containing Si
Authors: van Gurp G. J.
Published: January 2004

Electromigration-induced failure in Al films is retarded by the addition of Si. It is then governed by surface diffusion instead of by grain-boundary diffusion as it is in pure Al films. This is evidenced by activation energies, which were found to be 0.3 eV in Al/Si films and 0.55 eV in Al films. Failure in the Al/Si films is due to void formation in a temperature gradient near the cathode, whereas in Al films the failure mode is void formation at structural inhomogeneities.
Control of Positive Surface Charge in Si–SiO2 Interfaces by Use of Implanted Cs Ions
Authors: Sixt G. , Goetzberger A.
Published: January 2004

Cs is shown to give positive surface charge, which has great stability against temperature-bias stressing. Cs ions are first introduced into Si surfaces by ion implantation, then the surface layer is converted into SiO2 by thermal oxidation. Surface charge can be well localized by masking. Its magnitude depends on the number of implanted ions, on oxidation time, and temperature.
Infrared Holography with Wax and Gelatin Film
Authors: Kobayashi Shigeaki , Kurihara Kyoko
Published: January 2004

Holograms are made by CO2 laser (10.6 μm) utilizing the thermal deformation of wax and gelatin film. Reconstructed images of holograms are obtained in real time by 6328-Å He–Ne laser. These materials are found to be useful recording media for ir holography.
Laser-Induced Liquid Breakdown-a Step-By-Step Account
Authors: Felix M. P. , Ellis A. T.
Published: January 2004

The commonly observed phenomenon of breakdown in a liquid irradiated by a focused highpower laser is shown, by means of short-duration photography, to consist of a definite sequence of events starting with dielectric breakdown and rapidly expanding cavities in the focal region, followed by shock-wave propagation, cavity deceleration, localized cavitation, and eventual bubble collapse. This complete sequence has heretofore been obscured due to either time-exposure photography or lack of adequate time delay prior to taking photographs. This photographic sequence should settle the controversy over the origin of the many bubbles observed near the focal region of a liquid irradiated by a high-power pulsed laser.
Growth of High-Quality Garnet Thin Films from Supercooled Melts
Authors: Levinstein H. J. , Licht S. , Landorf R. W. , Blank S. L.
Published: January 2004

A new dipping technique is described for producing uniform-thickness low-defect-density magnetic garnet films suitable for bubble-domain devices. The technique is based on the observation that melts having the appropriate flux and garnet composition can be supercooled over a large temperature range and will remain supercooled, permitting the growth at constant temperature of epitaxial magnetic garnet films.
Supercurrent Tunneling Junctions with Tellurium Barriers
Authors: Seto John , Van Duzer Theodore
Published: January 2004

Uniformly distributed supercurrents have been observed in Josephson-like junctions using tellurium barriers with thicknesses up to 800 Å. Dependences of the maximum zero-voltage current on temperature and thicknesses are different from those of the normal-metal and oxide-barrier junctions. Typical junction resistances are comparable with those of oxide-barrier junctions.
Absolute Gain Measurements in a Multistage Dye Amplifier
Authors: Flamant P. , Meyer Y. H.
Published: January 2004

A six-stage flash-pumped dye amplifier using a rhodamine 6G solution is used for gain measurements. Amplification gains of up to 700 are obtained. Comparison of apparent amplification gains and absolute energy gains are made for different wavelengths emitted by a tunable dye oscillator. The possibility of achieving an effective energy gain of one order of magnitude by the use of a flash-pumped amplifier is demonstrated for wide beams.
Diffusion of Silicon into Tungsten in Field-Emission Microscope
Authors: Sinha M. K. , Swenson Orven F.
Published: January 2004

We report that when silicon is evaporated onto a tungsten field emitter at room temperature and the tip is then annealed at higher temperatures in order to carry out surface migration and thermal desorption studies, part of the silicon diffuses into the interior. When the tip is flashed at 2500 °K to produce a clean surface, all the silicon is not removed and it can be brought out again by annealing between 1000 and 1500 °K. This is demonstrated by a silicon buildup on the surface with an activation energy of 9.3 ± 0.5 kcal/mole. The rate of buildup is enhanced by the application of high voltage.
Optical Dielectric Strength of Alkali-Halide Crystals Obtained by Laser-Induced Breakdown
Authors: Yablonovitch Eli
Published: January 2004

CO2 laser-induced breakdown was studied in ten of the alkali halides. The bulk intrinsic breakdown thresholds are intimately related to the corresponding dc dielectric strengths. It is therefore concluded that the same mechanism is operative in both types of experiment. A method is proposed for designing more damage-resistant materials. In addition, the question of inclusions is dealt with.
pn-Schottky Hybrid Cold-Cathode Diode
Authors: Stolte C. A. , Archer R. J.
Published: January 2004

The device is a forward-biased GaAs0.6P0.4 pn-junction diode whose thin p layer is coated with a cesiated film of either Ag or Au 100–300 Å thick. In some cases the diodes are heat treated at 250 °C before cesiation. A cathodic emission efficiency of 1.4% is obtained at 10 A cm−2 for a heat-treated diode with a 100-Å-thick Au film. The emission is uniform over the coated surface and is proportional to exp(qV/kT). Preliminary data indicate long life for the device when operated in an ambient of Cs vapor.
High-Density Resonantly Sustained Plasma in a Variable-Length Cylindrical Cavity
Authors: Fredericks R. M. , Asmussen J.
Published: January 2004

It is demonstrated that linear bounded plasma theory can be used to understand and predict the high-power behavior of a resonantly sustained plasma inside a variable-length cylindrical cavity. Plasma densities of over 11 critical densities (> 1012 cm−3) can easily be produced by varying the cavity length.
Interfacial Barrier Effects in III-V Photoemitters
Authors: Bell R. L. , James L. W. , Antypas G. A. , Edgecumbe J. , Moon R. L.
Published: January 2004

Published data show strong evidence for the existence of an interfacial barrier on GaInAs photocathodes contrary to the claims made. Thermally assisted emission of photoelectrons over an interfacial barrier of height 1. 1 eV is shown here to explain the data. Energy distribution curves from a barrier-limited InAsP sample show that thermally assisted emission dominates over tunneling emission. The barrier height is shown to increase when Rb is substituted for Cs in the activation layer.
Characteristics of a Mode-Locked TEA CO2 Laser
Authors: Abrams R. L. , Wood O. R.
Published: January 2004

The pulse width of a mode-locked TEA CO2 laser has been accurately measured for the first time. The dependence of the pulse width on cavity modulation frequency and cavity loss has been determined. The results are evaluated in light of existing theory.
Implanted-Barrier Two-Phase Charge-Coupled Device
Authors: Krambeck R. H. , Walden R. H. , Pickar K. A.
Published: January 2004

A new kind of charge-coupled device (CCD) utilizing an ion-implanted barrier and only two nonoverlapping electrodes per bit is described. The use of implanted charge substantially simplifies device structure. The two-electrode-per-bit configuration permits operation with only one clock. In addition, the device performs better than any previously reported CCD with a loss per transfer of less than 0. 1% up to 6. 5 MHz and 2% at 17 MHz.
Diffusivity and Solubility of Si in the Al Metallization of Integrated Circuits
Authors: McCaldin J. O. , Sankur H.
Published: January 2004

Si was diffused along the evaporated Al layer of an integrated-circuit structure at temperatures between 360 and 560 °C, and the resulting concentration profile analyzed by electron microprobe. The Si solubility was found to agree with literature values for Si in wrought Al. The Si diffusivity was found to be substantially enhanced, however, probably due to a high density of imperfections in the evaporated Al film. Our measured diffusivities indicate an activation energy EA ≃ 0. 8 eV, about 40% less than the value for Si in wrought Al.
Direct Microscopic Simulation of Gunn-Domain Phenomena
Authors: Lebwohl P. A. , Price P. J.
Published: January 2004

An elaboration of the Monte Carlo computation of hot-electron states, such as to represent a time-dependent ensemble, is applied to the study of the instabilities associated with negative differential conductance. A two-band semiconductor model, approximately equivalent to GaAs, is used; and the instantaneous space-charge field parallel to the applied field is included in the particle dynamics. Spontaneous Gunn domains, successively traveling from cathode to anode at the expected speed, are obtained. This method should be suitable for investigating the instability phenomena on space and time scales shorter than are appropriate for the macroscopic theories.
Premixed cw Electric-Discharge CO Chemical Lasers
Authors: Ultee C. J.
Published: January 2004

cw lasing has been observed by discharging premixed CS2–O2. The spectral distribution of the output suggests a chemical-pumping mechanism. Additional observations on CS2 + O2 flames indicate the possibility of a flame laser.
Temperature Dependence of Structure on the I-V Curves of Superconducting Point Contacts
Authors: Puma Marcello , Deaver Bascom S.
Published: January 2004

In addition to the structure at V=2Δ/ne (2Δ is the energy gap, n is an integer), we observe prominent structure on the I-V curves of superconducting point contacts at V≫2Δ/e. We have studied the temperature dependence of all the structure and find some features vary like Δ(T) and others vary linearly with T4. These variations are interpreted in terms of a simple equivalent circuit model of the point contact and indicate that all of the features for clean point contacts are related to the Josephson Effect.
Double Heterojunction AlGaAsP Quaternary Lasers
Authors: Burnham R. D. , Holonyak N. , Korb H. W. , Macksey H. M. , Scifres D. R. , Woodhouse J. B. , Alfërov Zh. I.
Published: January 2004

Stimulated emission in AlGaAsP is demonstrated. Double heterojunction AlGaAsP lasers grown from Ga solution on GaAsP substrates exhibit 300 °K thresholds as low as 104 A/cm2 (∼ 8450 Å) and shift ∼ 450 Å to shorter wavelength at 77 °K. In spite of its more complicated crystalline structure, solution-grown AlGaAsP appears to exceed in quality vapor-grown GaAsP.
Spatial Variation of Radiative Recombination in GaAsP Wafer Revealed by Photoluminescence Image
Authors: Black J. F. , Summers C. J. , Sherman B.
Published: January 2004

A scanned laser microscope has been used to investigate the uniformity of luminescence in GaAs0.62P0.38 wafers. Large variations in the external quantum efficiency were observed. These variations are related to topographical features in the wafer surface that are associated with misfit-dislocation-line structures.
Superior Aluminum for Interconnections of Integrated Circuits
Authors: Bhatt H. J.
Published: January 2004

The electromigration strength of aluminum can be increased at least by more than ten times by the addition of aluminum oxide. Improvements in hillock formation, superior corrosion resistance, electrical resistivity similar to standard aluminum, and higher permissible annealing temperatures make aluminum-aluminum oxide alloy more attractive than standard aluminum for both bipolar and field-effect-transistor semiconductor technologies using single as well as multilevel metallization.
Investigation of the Composition of Sputtered Silicone Nitride Films by Nuclear Microanalysis
Authors: Croset M. , Rigo S. , Amsel G.
Published: January 2004

The composition and uniformity of silicon nitride thin films deposited by reactive sputtering in a mixture of argon and nitrogen eventually contaminated by oxygen traces were studied. Both direct observation of nuclear reactions on nitrogen and oxygen and backscattering of 4He+ ions were used to analyze the deposits. The films appear uniform as a function of depth. They are practically oxygen free but contain large amounts of argon. Their stoichiometry changes with the partial pressure PN2 of nitrogen. The ratios N/Si and Ar/Si vary in the opposite direction; for smaller values of PN2 there is an excess of silicon, whereas for larger values an excess of nitrogen is observed with respect to the stoichiometric composition Si3N4.
A Thin-Film Ring Laser
Authors: Weber H. P. , Ulrich R.
Published: January 2004

We report the operation and characteristics of a ring laser formed by a single-mode light-guiding thin film. The rhodamine 6G doped polyurethane film is coated on the surface of a cylindrical glass rod. This geometry establishes feedback for laser oscillation around the circumference of the rod. A nitrogen laser serves as pump source.
Electrical Properties of Silicon Diode Array Camera Targets Made by Boron Ion Implantation
Authors: Pickar K. A. , Dalton J. V. , Seidel H. D. , Mathews J. R.
Published: January 2004

Silicon diode targets used as the image-sensing element of video camera tubes have been successfully fabricated with one photolithographic step using boron ion implantation to form the array of ∼ 800 000 p+n diodes. Targets have been made reproducibly in this way with total leakage currents ≲ 10 nA at 12-V bias and 0–2 low-intensity white video defects per target. The results, which are insensitive to changes in dose and energy, show that heavily boron-implanted oxides can be annealed to give low-surface recombination velocity (S0 ∼ 7 cm/sec) and fixed charge (Qss/q ≃ 2.0 × 1011 cm−2). In addition, the bulk effective lifetime in the space-charge region of the implanted diodes is measured to be τ > 200 μsec.
Infrared-Pumped Visible Laser
Authors: Johnson L. F. , Guggenheim H. J.
Published: January 2004

Infrared-pumped stimulated emission near 6700 Å in BaY2F8 : Yb3+–Er3+ and at 5515 Å in BaY2F8 : Yb3+–Ho3+ is reported. In BaY2F8 : Yb3+–Er3+, oscillation takes place at 77 °K in Er3+ transitions from 4F9/2 to the highest level of the ground state at 410 cm−1. Pumping of Er3+ results predominantly from up-conversion produced by successive energy transfers from Yb3+; direct pumping of the metastable state and higher-lying states of Er3+ is substantially less effective than up-conversion. Oscillation in Ho3+ occurs in a transition from 5S2 to the highest level of the ground manifold at 385 cm−1. Up-conversion and direct pumping contribute about equally to the inversion.
Compensation of Radiation Effects by Charge Transport in Metal-Nitride-Oxide-Semiconductor Structures
Authors: Cricchi J. R. , Barbe D. F.
Published: January 2004

We consider the effects of ionizing radiation on complementary metal-nitride-oxide-silicon (CMNOS) structures for oxide thicknesses in the range 20–50 Å. The bidirectional radiation-induced threshold-voltage shifts in CMNOS structures are interpreted in terms of charge accumulation at the nitride-oxide interface. The electronic recovery of preirradiation threshold-voltage levels by carrier transport through the thin oxide is shown experimentally.
Hole Drift Velocity in Semi-Insulating CdTe
Authors: Canali C. , Ottaviani G. , Martini M. , Zanio K.
Published: January 2004

The velocity field characteristic of holes in semi-insulating CdTe has been measured using the time-of-flight technique in the space-charge limited mode. Ohmic behavior was found up to an electric field of 35 kV/cm. The measured mobility is 70 cm2V−1 sec−1. In the course of this experiment, the hole trapping time was also measured and found to be independent of the electric field.
Observation of Possible Leaky Plate Waves in a Plating Using Ultrasonic Reflectivity Measurements
Authors: Luukkala M. , Hattunen M.
Published: January 2004

The ultrasonic critical-angle reflectivity method has been employed to measure the phase velocity of dispersive plate waves in a cadmium or zinc layer on an iron substrate. Relatively good agreement with theoretical computations is obtained, although an unexpected below-cut-off wave was detected in cadmium plating but not in zinc plating.
MOSFET Ultrasonic Surface-Wave Detectors for Programmable Matched Filters
Authors: Claiborne L. T. , Staples E. J. , Harris J. L. , Mize J. P.
Published: January 2004

The piezoresistance effect in Si MOSFET p-channel inversion layers is utilized for the detection of elastic surface waves. Theoretical results for detector sensitivity are described. It is shown that arrays of such detectors can be used for programmable surface-wave signal processing. Variable delay-line operation and the correlation of phase-coded waveforms are demonstrated.
Effect of Source Resistance on Current-Voltage Characteristics of Superconducting Weak Links
Authors: Warman J. , Blackburn J. A.
Published: January 2004

The effect of finite source resistance on the computed current-voltage characteristics of superconducting weak links is considered for both capacitive and inductive devices. Hysteresis is found to vanish for a sufficiently small-source to shunt-resistance ratios.
Writing Characteristics of MnBi Films for Holographic Recording
Authors: Lee T. C. , Chen D.
Published: January 2004

In writing holograms on MnBi films, the two important parameters are the total beam energy and the thermal modulation depth, both imposed by the physical properties of the film. Different combinations of the two parameters lead to different types of holograms. Experimental results will be given to demonstrate the predicted varieties of recordings. Accurate measurements of diffraction efficiencies and interpretations of the result will be given.
Hafnium-Silicon Schottky Barriers: Large Barrier Height on p-Type Silicon and Ohmic Behavior on n-Type Silicon
Authors: Saxena A. N.
Published: January 2004

Schottky-barrier diodes of Hf on p-type Si gave a height φMS = 0.90 eV, which is the largest value of φMS reported to date on Schottky barriers on either p- or n-type Si. Excellent agreement was found between the φMS values determined from current-voltage, activation energy, and capacitance-voltage analyses. This large value of φMS of the Hf-(p)-Si Schottky barrier allows several new applications which were not possible before in the integrated circuit technology, such as clamping of p-n-p transistors and fabrication of enhancement-mode p-channel Schottky gate field-effect transistors. Hafnium deposited on n-type Si (ND≅5×1015 cm−3) gave Ohmic behavior suggesting the validity of the work-function-difference model for the Hf–Si system. Under this assumption, the Schottky-barrier analysis gives the work function of Hf=4.23±0.02 eV.
Frequency Dependence of Superconducting Cavity Q and Magnetic Breakdown Field
Authors: Rabinowitz Mario
Published: January 2004

A theoretical explanation is given to account for the unexpected observation that L- and S-band Nb superconducting cavities were found to have lower Q and lower magnetic breakdown field than those of the higher X-band frequencies. Both effects can be related to the trapping of magnetic flux in the cavity walls. The frequency dependence arises from the frequency dependence of the resistivity of oscillating fluxoids. Calculations based on this model are in agreement with experimental observations.
Effect of Alloy Additions on Electromigration Failures in Thin Aluminum Films
Authors: Gangulee A. , d'Heurle F. M.
Published: January 2004

In earlier work with aluminum thin films, electromigration through grain boundary diffusion has been found to be reduced by the addition of small amounts of copper and not to be affected by additions of silver and gold. Additions of other alloying elements having large atomic-size differences with respect to aluminum, namely, magnesium, nickel, and chromium, have now also been shown to reduce the rate of electromigration.
Cross-Beam Electric-Discharge Convection Laser
Authors: Eckbreth Alan C. , Davis Jack W.
Published: January 2004

An experimental investigation of a 60-cm-wide × 2.5-cm-high N2–CO2 cross-beam electric-discharge convection laser (EDCL) is described. Experiments relating to the achievement of uniform and stable discharges in the rectangular channel and measurements of laser optical properties are reviewed.
Millimeter and Submillimeter Wave Laser Action in Symmetric Top Molecules Optically Pumped via Parallel Absorption Bands
Authors: Chang T. Y. , McGee J. D.
Published: January 2004

Twenty-one new laser lines with wavelengths from 192.8 μm to 1.8144 mm have been observed in methyl fluoride, acetonitrile, and methyl acetylene pumped by a CO2 laser. A novel form of high precision spectroscopy based on the relationships among the emission and absorption wavelengths is also described.
Ferroelastic Behavior of PLZT Ceramics When Subjected to Large Tensile Strains
Authors: Meitzler A. H. , O'Bryan H. M.
Published: January 2004

Thin plates of perovskite ferroelectric lead lanthanum zirconate titanate (PLZT) ceramics bonded to plastic substrates strained in flexure have shown the ability to withstand large tensile strains (∼10−3). This ability results from two interrelated mechanisms: (i) a structural phase change, and (ii) ferroelastic switching of the polarization direction. In the experiments on which these conclusions are based, crystal structure was determined from x-ray data and strain was determined from both x-ray and resistance wire strain gauge data. The results presented here establish that PLZT materials show ferroelastic behavior.
0.2-W Repetitively Pulsed Flashlamp-Pumped Dye Laser
Authors: Mack M. E.
Published: January 2004

Using a novel fast risetime flashlamp pulsed at 10–50 pps with up to 50 J per pulse, laser emission has been obtained from a number of dyes with average outputs ranging to 200 mW.
Magnetization Properties of Nonideal Type-II Superconductors Transporting Sinusoidal Alternating Current in a Longitudinal Magnetic Field
Authors: Sugahara M. , Kato S.
Published: January 2004

Observations are presented on the ac magnetization of Nb-25% Zr and Nb-48% Ti wires in a longitudinal field Hz0. When Hz0 is higher than the field induced by the impressed ac conduction current, the magnetization data agree with the calculation based on a force-free model. The magnetization process of Nb–Zr shows a large deviation from the usual critical state behavior.
Infrared Photon Counting by Ge Avalanche Diodes
Authors: Haecker W. , Groezinger O. , Pilkuhn M. H.
Published: January 2004

Germanium avalanche diodes with statistically independent microplasma pulses have been successfully used as very sensitive photon counters at 77°K and at photon energies near 0.8 eV. The dark pulse rate at low temperatures was found to be limited by band-to-band tunnelling of carriers, and at high temperatures by thermal generation of minority carriers. Tunnel-assisted absorption was observed at energies slightly smaller than the band gap.
Filamentary Conduction in VO2 Coplanar Thin-Film Devices
Authors: Duchene J. , Terraillon M. , Pailly P. , Adam G.
Published: January 2004

Filaments have been observed in VO2 coplanar thin-film devices and their I-V characteristic investigated. An analysis of the evolution of the temperature profile in the VO2 film is given.
High-Efficiency Room-Temperature 2.06-μm Laser Using Sensitized Ho3+:YLF
Authors: Chicklis E. P. , Naiman C. S. , Folweiler R. C. , Gabbe D. R. , Jenssen H. P. , Linz A.
Published: January 2004

Pulsed room-temperature laser action at 2.06 μm has been achieved using Ho3+:YLF (LiF4) sensitized with Er3+ and Tm3+. An unoptimized cavity gave a threshold of 35 J and a slope efficiency of 1.3% in normal mode with an output mirror of 62% T. A slope efficiency of 2% and a 65-J threshold were observed in Q-switched operation along with Q-switched energy of >500 mJ from a 0.9×⅛-in. rod. The sensitizer ions have broad absorption bands and transfer times (to the active ion) of 150–200 μsec.
Infrared Spectroscopy of CO Using a Tunable PbSSe Diode Laser
Authors: Nill K.W. , Blum F.A. , Calawa A.R. , Harman T.C.
Published: January 2004

The P(9) fundamental infrared absorption line of carbon monoxide at 2107.4 cm−1 has been studied with high resolution using a cw current tunable PbS0.82Se0.18 diode laser. Both the Doppler linewidth of 150 MHz and the absorption coefficient at line center of 2.1 cm−1/Torr at room temperature have been measured directly for the first time with an estimated resolution of 1% of the linewidth.
Preferential Oxidation of Fe in Permalloy Films
Authors: Bajorek C.H. , Nicolet M-A. , Wilts C.H.
Published: January 2004

On the basis of He-ion backscattering, x-ray fluorescence, and complementary measurements, it is unambiguously established for the first time that the oxide layer on the surface of oxidized 81% Ni-19% Fe evaporated films is predominantly Fe-oxide. Extrapolation of results for pure iron films indicates that the oxide is most likely antiferromagnetic α-Fe2O3. On the basis of ferromagnetic resonance measurements, it is concluded that the oxide negligibly affects the pinning of the bulk spins at the film-oxide interface.
Comment on ``p-Type Conduction in Li-Doped ZnSe''
Authors: Dieleman J.
Published: January 2004

p-type conduction in Li-doped ZnSe has been reported earlier, and the level at 0.62 ± 0.02 eV above the valence band observed in this material has been identified with trivalent Fe substitutionally incorporated on a Zn site.
Reply to ``Comment on `p-Type Conduction in Li-Doped ZnSe'''
Authors: Park Y.S.
Published: January 2004

We reply to J. Dieleman on his comment on ``p-Type Conduction in Li-Doped ZnSe''. All four references cited by Dieleman do not prove p-type conductivity in Li-doped ZnSe. We have presented for the first time concrete evidence of p-type conduction in Li-doped ZnSe by presenting the data on transport measurements.
Zn Displacement Threshold in ZnTe
Authors: Meese J.M.
Published: January 2004

The energy required to displace Zn atoms in ZnTe by irradiation with energetic electrons has been measured. Above an electron beam energy of 185 keV, corresponding to a maximum recoil energy of 7.35 eV for Zn atoms, the near-band-edge cathodoluminescence is observed to increase in intensity with increasing fluence. This rate of increase is proportional to the square of the electron beam energy near the displacement threshold.
Observation of Infrared-Microwave Two-Photon Transitions in NH3
Authors: Oka Takeshi , Shimizu Tadao
Published: January 2004

An infrared-microwave two-photon absorption is observed in 15NH3. A tunable frequency of microwave radiation is ``added'' to a fixed frequency of laser radiation utilizing the nonlinearity of the molecular absorption. This method will be useful for high-resolution infrared spectroscopy and for experiments which use laser radiation for pumping molecular energy levels.
Effects of Radiation on Surface Resistance of Superconducting Niobium Cavity
Authors: Halama H.J.
Published: January 2004

The author has made the first measurements of radiation damage in a superconducting niobium cavity operated at microwave frequencies. It is shown that even a rather low radiation level of 1015 protons/cm2 with an energy of 175 MeV increases significantly the residual surface resistance at high power levels. These data are very pertinent to the construction of superconducting linear accelerators.