摘要:

A steady two‐dimensional magnetohydrodynamic boundary‐layer flow on a flat plate with a uniform transpiration through the plate which is kept at a constant temperature is considered. Heat transfer at the plate is found to increase with the Joule heating, the transpiration number, the magnetic interaction number, and the Prandtl number. The temperature profile is substantially altered by transpiration, magnetic interaction, and the Prandtl number.

ISSN:0021-8979    

DOI:10.1063/1.337706

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We extend our previous analytical modeling of the dynamic response of shock loaded piezoresistance gauges to the unloading region. We present a new approach in which we use the measured resistive hysteresis of manganin gauges to get their release stress‐strain characteristics. This procedure is especially suited for manganin gauges because their resistive response depends only on the stresses and strains which prevail in them. Other gauge materials which are sensitive to the temperature rise and/or shock generated defects would not lend themselves to this direct analysis. We present an example in which we calculate the unloading stress‐strain curve for manganin from a shock level of 120 kb down to zero longitudinal stress. Various aspects of this curve are discussed and compared to data obtained by other techniques.

ISSN:0021-8979    

DOI:10.1063/1.337707

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Low‐temperature photoluminescence (PL) spectra for Si‐doped AlAs grown by molecular‐beam epitaxy is reported for the first time. It is revealed that a sharp emission which is 63 meV below the indirect excitonic band gapEg,ind(X) is related to the Si‐donor level. From the dependence of PL spectra upon Si dosage, it is suggested that a broad emission band which is 135 meV belowEg,ind(X) is due to donor‐acceptor (SiAl‐SiAs) pair recombinations.

ISSN:0021-8979    

DOI:10.1063/1.337708

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Spatial distribution of defects near the cleaved surface of InSe is determined by means of the ion‐channeling technique. The luminescence spectra of InSe crystals with low defect concentration show three lines above 1.330 eV at 14 K. The specimens with high defect concentration show broad emission peaks at around 1.32 eV.

ISSN:0021-8979    

DOI:10.1063/1.337709

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

A new process—simultaneous implantation and diffusion annealing—has been developed for the formation ofpnjunctions in compound semiconductors. It combines implantation and diffusion, by using doped SiO2spin‐on films simultaneously as a surface protection during activation of the implants and as a diffusion source. Only a single annealing step is necessary, which is very important for a careful heat treatment of existing semiconductor structures. Examples are presented for GaInAs. Thenlevel formed by Si implantation varies from 1×1017cm−3to 6×1018cm−3, with an increasing dose. Theplevel is adjusted to about 1×1019cm−3by the amount of Zn salt in the spin‐on solution. The position of thepnjunction is shifted by the annealing step.

ISSN:0021-8979    

DOI:10.1063/1.337710

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Zn diffusion into 2‐in.‐diam semi‐insulating GaAs wafers has been carried out by a simple, open‐tube diffusion method using a commercially available GaAsZn solid source and without surface coating or encapsulation. High‐quality (&mgr;=75–100 cm2/V s) layers with a flat carrier concentration and sharp cutoff Zn distribution have been obtained. Thep‐type layers obtained by this method are uniform across the wafer, and the technique can be easily scaled up. Selective diffusion of Zn was also demonstrated with this technique, using a plasma‐deposited Si3N4as a diffusion mask.

ISSN:0021-8979    

DOI:10.1063/1.337711

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Multiple magnetic films composed of alternating magnetic and nonmagnetic layers may have a layered domain structure when there is no exchange coupling through the nonmagnetic layers. As demonstrated for an Fe‐Cu multilayer thin film, this structure can be made visible in Schlieren images using a particular variant of Foucault–Lorentz transmission electron microscopy.

ISSN:0021-8979    

DOI:10.1063/1.337712

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.337713

出版商:AIP    

年代:1986

数据来源: AIP