摘要:

Recent photographic and interferometric measurements, obtained by Maietal., on an arc driven in air between parallel electrodes by a transverse magnetic field are examined. The interpretation, proposed by Mai, based on a continuous growth of a transition region in front of the moving arc is shown to be highly questionable. By contrast, the generally accepted existence of a double‐vortex flow in the arc core is shown to account for the results.

ISSN:0021-8979    

DOI:10.1063/1.328176

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

A direct transfer of results developed for long arcs balanced magnetically against gas crossflows to explain the behavior of short high‐power moving arcs can offer misleading conclusions if due care is not paid to fundamental assumptions of the models employed. A thermal wave description of the leading edge to arc systems traveling at a significant fraction of the sonic speed is defended as a reasonable alternative to arguments based upon analogy.

ISSN:0021-8979    

DOI:10.1063/1.328177

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The fraction of Te atoms accumulated on the surface after pulsed laser melting of ion‐implanted silicon depends on the implantation range. The experimental profiles can be fitted by a numerical calculation, taking into account the diffusion in the liquid phase, the interface velocity, and the interfacial distribution coefficient which is much higher than the equilibrium one. The comparison between the spatial extent of the initial transient, well‐known from the standard theory of normal freezing, and the implantation range determines the fraction of surface accumulation.

ISSN:0021-8979    

DOI:10.1063/1.328178

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The results of several independent investigations of tracer diffusion and/or ionic conductivity in single crystals of SrCl2are reviewed briefly. It is shown that, despite the considerable experimental difficulties presented by this substance, good agreement is found for the majority of the results. Where disagreement exists, it seems probable that the experimental specimens were not chemically treated rigorously enough.

ISSN:0021-8979    

DOI:10.1063/1.328179

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

Solid phase regrowth of Si on sapphire has been investigated in the Si (amorphous)/Al (poly)/Al2O3(crystal) system. Using transmission electron microscopy, scanning electron microscopy, Auger electron spectroscopy, and Hall‐effect measurements, it has been shown that Si is transported through an Al film at 550 °C to producep‐type Si films on the sapphire substrate. The growth process has been shown to be initiated at Si nucleation sites on the substrate. These sites expand by mass accretion, forming island structures that coalesce to yield continuous large grained polycrystalline Si films on the sapphire surface.

ISSN:0021-8979    

DOI:10.1063/1.328180

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The remarkable unity found in the high‐field behavior of thin‐film amorphous chalcogenides is illustrated by comparing pulse data ranging from nanosecond to millisecond duration. Sixteen long‐pulse effects had earlier been described in detail by coupled carrier theory, which postulates one lower‐energy carrier, localized by hopping or trapping below a band, and one higher‐energy carrier, which is free within a band to ionize the localized carrier. Twelve new tests of this theory against short‐pulse data are given in four materials and without the use of adjustable parameters. Very substantial agreement is found in both calculated magnitudes and in predicted functional dependences. The use of short pulses in unswitched materials renders joule heating negligible in all tests of theory against experiments reported here.

ISSN:0021-8979    

DOI:10.1063/1.328181

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

A new method to detect deep centers close to the interface in metal‐semiconductor contacts is reported. The presence of humps in the logIF‐VFcharacteristics attributed to resonant tunneling contributions to the total forward current is investigated via the slope changes in the logIF‐VFplots. Although the relation between the voltageVFmat which the minimum ofd2 logIF/dV2Foccurs, and the energy position of the levels causing the resonant tunneling current is not easy to calculate, this new method represents a powerful means to detect traps lying near the interface.

ISSN:0021-8979    

DOI:10.1063/1.328182

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The efficiency of the 3.0‐eV photoluminescence band which results from optical excitation into the 6.1‐eVFband in single‐crystal sapphire is much weaker forFcenters introduced by fast neutron bombardment than for those produced thermochemically (i.e., by either deliberate additive coloration or by coloration during growth). The luminescent efficiency has been monitored at room temperature following successive isochronal annealing stages up to 580 °C for samples exposed to ∼1017neutrons cm−2. The relative emission intensity perFcenter increased rapidly as theFcenters were thermally destroyed and reached a value at the upper end of the annealing range which was 40 times the preanneal value. It is suggested that the initial relatively weak emission is due to concentration quenching which results from the highly inhomogeneous distribution of lattice defects, i.e., displacement cascades, produced by fast neutron bombardment.

ISSN:0021-8979    

DOI:10.1063/1.328183

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

Photoluminescence (PL) studies were performed at 2 K for nitrogen (N)‐implanted and N‐free In0.30Ga0.70P crystals, which were grown by a step‐cooling liquid‐phase‐epitaxial method. For the N‐implanted In0.30Ga0.70P, an isoelectronic trap was found to be formed at annealing temperature over 600 °C. The binding energy of the excitons bound to the above traps was determined to be 92 meV from the temperature dependence of the PL spectra.

ISSN:0021-8979    

DOI:10.1063/1.328184

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

A computer analysis of heteroface solar cells with thin window layer has been performed regarding the effects of multiple reflections in the window layer, as well as in antireflection layers. It is shown that the thickness of the window layer greatly affects the reflection characteristic of the cell, and there is an optimum thickness for the window, so the window layer thickness must be defined so as to minimize the reflection loss, as well as the absorption loss by the window.

ISSN:0021-8979    

DOI:10.1063/1.328185

出版商:AIP    

年代:1980

数据来源: AIP