APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

1 Mar 1973

Volume 22, Issue 5, pp. 203-264


Thermoelectricity in tungsten at low temperatures

J.C. Garland

Appl. Phys. Lett. 22, 203 (1973); http://dx.doi.org/10.1063/1.1654610 (3 pages) | Cited 3 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
Measurements of the thermoelectric properties of pure tungsten have been made between 1.2 and 7.0 K by a method in which the electric field within the metal was nulled by the simultaneous application of heat and electric currents. An unusual dependence of the thermoelectric properties on impurity concentration was observed below 3 K; these results are compared with conventional thermoelectric power measurements over the same range of temperatures.

Electron avalanche breakdown induced by ruby laser light

David W. Fradin and Michael Bass

Appl. Phys. Lett. 22, 206 (1973); http://dx.doi.org/10.1063/1.1654611 (3 pages) | Cited 15 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
Ruby‐laser‐induced intrinsic bulk damage in nine alkali‐halide crystals is reported. Within experimental error and for all of these crystals the damage field is greater than or equal to that measured at 1.06 μm and dc. The trend in breakdown fields among these crystals at 0.69 μm differs from that at longer wavelengths and suggests that, even though electron avalanche breakdown is the likely damage mechanism, the first signs of a frequency dependence to this process appear by 4.3×1014 Hz.

Growth‐induced magnetic anisotropy in Y2.4Eu0.6Ga1.2Fe3.8O12

F.B. Hagedorn, S.L. Blank, and R.L. Barns

Appl. Phys. Lett. 22, 209 (1973); http://dx.doi.org/10.1063/1.1654612 (2 pages) | Cited 9 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
Torque magnetometer measurements on epitaxial magnetic garnet films of nominal composition Y2.4Eu0.6Ga1.2Fe3.8O12 have identified a growth‐induced noncubic magnetic anisotropy of 8000 erg∕cm3 which anneals away after several hours at 1300°C. Precision x‐ray measurements show that the film lattice constant changes by not more than 0.0003 Å during this annealing process. These results are similar to previous observations made on epitaxial films of other compositions but are contrary to earlier reports of Geiss et al., Klokholm et al., and Cronemeyer et al. who had concluded that the noncubic anisotropy in Y☒Eu films was exclusively stress induced and who reported large changes in film lattice constants with annealing.

Impulse loading of targets by subnanosecond laser pulses

S.A. Metz

Appl. Phys. Lett. 22, 211 (1973); http://dx.doi.org/10.1063/1.1654613 (3 pages) | Cited 16 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
Measurements of the impulse received by graphite and aluminum targets exposed to a 250‐psec laser pulse are reported. Experiments were conducted in air and vacuum at incident energies between 0 and 20 J. In both environments, there is a definite energy threshold, which is lower in air than in vacuum, below which no momentum is transferred. For a given energy above threshold, the impulse generated in air is greater than in vacuum.

The revealing of information concealed in overexposed x‐ray topographs

S. Mardix

Appl. Phys. Lett. 22, 214 (1973); http://dx.doi.org/10.1063/1.1654614 (2 pages) | Cited 3 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
Thick photographic emulsions are used with weakly absorbed radiations. These emulsions are capable of photographic densities much higher than 1.5. High‐density areas appear black, and photographic details are lost when viewed with transmitted light. Reflected‐light techniques can reveal those details. Application to x‐ray topography is demonstrated.

Nanosecond pulse amplification in electron‐beam‐pumped CO2 amplifiers

J.F. Figueira, W.H. Reichelt, G.T. Schappert, T.F. Stratton, and C.A. Fenstermacher

Appl. Phys. Lett. 22, 216 (1973); http://dx.doi.org/10.1063/1.1654615 (3 pages) | Cited 20 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
Pulse amplification and energy extraction experiments in high‐pressure CO2 amplifiers indicate that the effective rotational time constant for nanosecond energy extraction is an order of magnitude larger than the rotational relaxation time.

Effects of atmosphere during arsenic diffusion in silicon from doped oxide

T. Sakurai, H. Nishi, T. Furuya, H. Hashimoto, and H. Shibayama

Appl. Phys. Lett. 22, 219 (1973); http://dx.doi.org/10.1063/1.1654616 (2 pages) | Cited 1 time

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
The effects of N2 and O2 atmospheres on arsenic diffusion in silicon from a doped oxide are studied by the backscattering method. The results indicate that the amounts of arsenic atoms diffused in silicon in a N2 atmosphere are smaller than those in an O2 atmosphere. This is caused by the differences in the properties of the silicon‐doped oxide interface during diffusion; the elemental arsenic is accumulated at the oxide side of the interface during diffusion in N2, whereas arsenic remains in the state of an arsenic oxide during diffusion in O2 and is not accumulated.

An ultrasonic technique for measuring the absolute signs of photoelastic coefficients and its application to fused silica and cadmium molybdate

D.K. Biegelsen

Appl. Phys. Lett. 22, 221 (1973); http://dx.doi.org/10.1063/1.1654617 (3 pages) | Cited 7 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
A simple dynamic technique for the determination of the absolute signs of photoelastic coefficients is described. The method consists of comparing the known phase of a standing acoustic wave with the phase of the deflection of a photoelastically refracted laser beam, the waist of which is small compared with an acoustic wavelength. Experimental verification of the technique is presented along with specific limitations. The method forms a convenient complement to the Bragg diffraction measurement of the magnitudes of photoelastic coefficients.

Photocurrent measurements on GaP : N green‐light‐emitting diodes

H. Kressel and I. Ladany

Appl. Phys. Lett. 22, 224 (1973); http://dx.doi.org/10.1063/1.1654618 (3 pages) | Cited 7 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
Photocurrent measurements are shown to provide a convenient technique for determining the nitrogen concentration in the active region of GaP diodes designed for green light emission. The strength of the photocurrent peak at the A‐line energy can be correlated semiquantitatively with the diode efficiency in devices which differ only in their nitrogen content. Room‐temperature photocurrent measurements of Schottky barrier diodes formed by gold evaporation on epitaxial material can be similarly used for determining the relative nitrogen concentration.

Minority‐carrier lifetimes and luminescence efficiencies in nitrogen‐doped GaP

P.D. Dapkus, W.H. Hackett, O.G. Lorimor, G.W. Kammlott, and S.E. Haszko

Appl. Phys. Lett. 22, 227 (1973); http://dx.doi.org/10.1063/1.1654619 (3 pages) | Cited 30 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
Photoluminescence and scanning‐electron‐microscope measurements of minority‐carrier lifetime and luminescence efficiency have been made on Zn, N‐doped and Te, N‐doped GaP liquid‐phase‐epitaxy layers. Nitrogen concentrations are held constant at 1 × 1019 cm−3, while the majority‐carrier concentrations were varied between 5 × 1016 and 5 × 1018 cm−3. It is shown that, for excitation levels equivalent to 10 A∕cm2 diode diffusion current density, a maximum external luminescence efficiency (in air) of 0.3% is measured for ∼1018‐cm−3 Zn, N‐doped GaP, in contrast to a maximum efficiency of 0.06% for ∼1017‐cm−3 Te, N‐doped GaP. These results suggest that significantly higher electroluminescent efficiencies approaching 0.3% are available for diodes at 10 A∕cm2, by increasing injection into ∼1018‐cm−3 Zn, N‐doped GaP.

Threshold switching in chalcogenide glass films

S.H. Lee and H.K. Henisch

Appl. Phys. Lett. 22, 230 (1973); http://dx.doi.org/10.1063/1.1654620 (2 pages) | Cited 7 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
On the basis of polarization arguments, the equality τd=τl is proposed as the critical condition for the threshold point of chalcogenide glass switches, τd being the dielectric relaxation time and τl the carrier lifetime. It is shown that this switching criterion is in good agreement with measurements and that it explains the temperature dependence of the threshold voltage as well as the voltage dependence of the delay time.

Experimental flux shuttle

T.A. Fulton and L.N. Dunkleberger

Appl. Phys. Lett. 22, 232 (1973); http://dx.doi.org/10.1063/1.1654621 (2 pages) | Cited 23 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
We report the operation of an experimental model of the Josephson junction shift register known as the flux shuttle.

Voigt magnetoabsorption in semiconductors at low temperature

G.P. Srivastava and P.C. Kothari

Appl. Phys. Lett. 22, 234 (1973); http://dx.doi.org/10.1063/1.1654622 (2 pages)

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
A compensation bridge for measuring Voigt magnetoabsorption is set up for X band. Phase and amplitude measurements as a function of magnetic field are done on two n‐type Ge crystals, having resistivities of 11. 9 and 4. 1 Ω cm at 89°K. The magnetic field is applied perpendicular to the direction of propagation and parallel to the microwave electric field (longitudinal case). Theoretical calculations are done by taking into account the mixed scatterings of lattice and impurities. The estimated values of the mobilities due to lattice scattering and impurity scattering are also presented.

Determination of the origin of the 10.6‐μm absorption in CO2 laser window materials

J.R. Hardy and B.S. Agrawal

Appl. Phys. Lett. 22, 236 (1973); http://dx.doi.org/10.1063/1.1654623 (2 pages) | Cited 18 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
Theoretical studies are presented which show that it should be possible to determine whether the absorption at 10. 6 μm in alkali halides is due to impurities or whether it is intrinsic. These studies show that the temperature dependence of the measured absorption should be very different for intrinsic multiphonon absorption as compared with defect‐activated absorption.

Ion‐implantation‐damage gettering effect in silicon photodiode array camera target

C.M. Hsieh, J.R. Mathews, H.D. Seidel, K.A. Pickar, and C.M. Drum

Appl. Phys. Lett. 22, 238 (1973); http://dx.doi.org/10.1063/1.1654624 (3 pages) | Cited 15 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
The use of ion implantation damage to getter deleterious impurities from diode space‐charge regions is studied. Ion implantation into the neutral regions near p‐n junctions is shown to cause substantial reduction in the incidence of the type of white video defects (excessive‐leakage current diodes) caused by impurity precipitation and often found in a cyclonic pattern. It is found that using doses of 1016 cm−2 phosphorus (50 keV), ≥1015 cm−2 arsenic (150 keV), and ≥3×1015 cm−2 argon (50 keV) can completely eliminate these defects. In addition, the dark currents of the targets which receive ion implantation is equivalent to or lower than control slices receiving regular phosphorus gettering. From curves of the dark current vs target voltage, it is estimated that the surface recombination velocity (S0) of the ion‐implanted slices is ∼20% lower than S0 in the control slices, while the Si☒SiO2 interface fixed‐charge density is not affected by ion implantation. By comparing the gettering efficiency of P+‐, As+‐, and Ar+‐implanted slices, it is concluded that the damage layer rather than the presence of an implanted n+ region is responsible for the observed gettering behavior.

Pulse amplitude modulation of a CO2 laser in an electro‐optic thin‐film waveguide

P.K. Cheo

Appl. Phys. Lett. 22, 241 (1973); http://dx.doi.org/10.1063/1.1654625 (4 pages) | Cited 9 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
Beam steering of a 10. 6‐μm guided‐wave mode in an electro‐optic GaAs thin‐film waveguide is observed. The deflection angle increases linearly with increasing voltage and interaction length. A switching time of about 60 nsec has been obtained and is limited by the detector response. This technique has been used to obtain more than 12% amplitude modulation of a CO2 laser by applying only 50 V to an ∼20‐μm‐thick GaAs thin‐film waveguide having a total interaction length of 0. 5 cm.

Laser‐induced gas breakdown in the presence of preionization

Robert T. Brown and David C. Smith

Appl. Phys. Lett. 22, 245 (1973); http://dx.doi.org/10.1063/1.1654626 (3 pages) | Cited 33 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
Experiments have been carried out to study the ionization buildup and gas breakdown processes in the focal volume of an intense 10. 6‐μ laser pulse in atmospheric‐pressure helium preionized to various levels of electron density. With no preionization the laser flux required for breakdown was in agreement with results obtained by previous authors, and showed the same dependence on the focal volume size. However, with a high initial electron density, the threshold was much lower and showed no volume dependence. The results indicate that with preionization the breakdown threshold is controlled by cascade ionization processes, while with no preionization it is dominated by other effects such as small impurity particles in the gas, and that these other effects may be responsible for the diameter dependence of the breakdown threshold.

Performance of an unstable repetitive pulsed CO2 laser oscillator

J. Davit and C. Charles

Appl. Phys. Lett. 22, 248 (1973); http://dx.doi.org/10.1063/1.1654627 (3 pages) | Cited 4 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
Mode control experiments were performed with an unstable TEA repetitive pulsed CO2 laser oscillator. Near‐ and far‐field intensity distributions were obtained that are consistent with theoretical values for a diffraction‐limited beam. Performance of the same laser with a stable optical cavity is also given as a reference.

Submillimeter waveguiding on periodic metal structure

R. Ulrich and M. Tacke

Appl. Phys. Lett. 22, 251 (1973); http://dx.doi.org/10.1063/1.1654628 (3 pages) | Cited 43 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
Electromagnetic radiation of 337‐μm wavelength has been guided in the form of TM surface waves along thin copper sheets perforated in a regular pattern (metal mesh). Polyethylene prism couplers served for launching and output coupling. The frequency dispersion of the metal mesh guide is similar to that of a transmission line loaded periodically with shunt capacitances. Strong directional dispersion is observed.

Measurement of V‐V transfer rate from HF v = 3 using simultaneous optical pumping on the HF v = 2 → 1 and v = 1 → 0 bands

R. M. Osgood, P. B. Sackett, and A. Javan

Appl. Phys. Lett. 22, 254 (1973); http://dx.doi.org/10.1063/1.1654629 (3 pages) | Cited 12 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
A measurement of the (predominantly) vibration‐vibration (V‐V) decay rate of the v = 3 level in HF gas yields a value of 1.6×106 sec−1 Torr−1. The technique utilized was to optically pump the HF sample with the output of a pulsed HF laser oscillating simultaneously on a line in both the v = 2 → 1 and v = 1 → 0 bands. An analytic description of the time behavior of the v = 1, v = 2, and v = 3 levels using a treatment based on simplified rate equations is described.

The extent of crystallization resulting from submicrosecond optical pulses on Te‐based memory materials

R. J. von Gutfeld

Appl. Phys. Lett. 22, 257 (1973); http://dx.doi.org/10.1063/1.1654630 (2 pages) | Cited 7 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
Thermal profiles resulting from a laser‐induced melt‐quench cycle of a Te‐based chalcogenide film on Mylar have been determined. These data are combined with experimentally obtained crystallization rates of Weiser et al. to determine the extent of crystallization that may occur in regions adjacent to the laser‐produced amorphous region. A maximum fractional crystallization of less than 10−2 is found which indicates that no crystalline halo is expected to surround such an amorphous region. Thus, the extent to which photocrystallization plays a role in these alloy materials appears still to be an unanswered question.

Base‐line noise reduction in laser pulse trains

James M. Thorne, Thomas R. Loree, and Gene H. McCall

Appl. Phys. Lett. 22, 259 (1973); http://dx.doi.org/10.1063/1.1654631 (2 pages) | Cited 8 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
The intensity‐dependent rotation of elliptically polarized light by carbon disulfide is used to discriminate against low‐intensity laser light and pass high‐intensity pulses through crossed polarizers. The transmitted intensity is shown to be proportional to the third power of the incident intensity. This technique has been used to reduce base‐line noise and low‐intensity pulses in the output pulse train of a mode‐locked Nd : YAG oscillator.

Dislocations in thermally stressed silicon wafers

S.M. Hu

Appl. Phys. Lett. 22, 261 (1973); http://dx.doi.org/10.1063/1.1654632 (4 pages) | Cited 9 times

Online Publication Date: 16 October 2003

Full Text: | Download PDF

Show Abstract
To the author's knowledge, this is the first letter on the dislocation structures generated in silicon wafers by thermal stresses. These dislocations were caused by cooling in a room‐temperature ambient on removal from a furnace. The 〈110〉 60° type was dominant, although 〈112〉 dislocations were also observed. Their most important feature is that they tend to seek the shortest allowable paths in passing through the wafer thicknesswise. They often form fairly regular arrays in single or closely neighboring {111} planes, thus producing ensembles of etch pits (or mounds) that macroscopically resemble slip lines. The dislocation densities were often ∼104 cm−2; these values agreed within an order of magnitude with those predicted by a simple stress relief mechanism.
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close