摘要:

Ion implantation of carbon in the AISI 52100 bearing steel yields a distinct reduction in friction and wear. This improvement is strongly dependent on the implanted fluence. The coefficient of friction decreases from 0.6 to 0.2 for doses >1×1018cm−2(energy 100 keV) and a wear reduction to nearly ‘‘zero wear’’ was obtainable even under severe wear conditions. The counterpart (unimplanted AISI 52100 steel ball) shows a similar behavior, which demonstrates that the tribological system is totally changed. Mo¨ssbauer spectroscopy and x‐ray diffraction revealed that hexagonal &egr;‐carbide is formed on implantation. On the other hand, Rutherford backscattering spectrometry shows that for high doses a large fraction of the implanted carbon is not contained in this carbide.

ISSN:0003-6951    

DOI:10.1063/1.104067

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A new type of light transducer has been designed consisting of an organic electroluminescent (EL) diode on a photoconductive amorphous silicon carbide (a‐SiC:H) film as an electron photoinjecting electrode. Input light received by a photosensitivea‐SiC:H film is transduced to the output light with a different wavelength emitted from an EL diode in the layered configuration. The input‐light pattern was well kept spatially in the output. The EL output light was controllable with dc voltage applied to the device and input‐light intensity. These features are suggested to be potentially applicable for a new type of the spatial light modulator.

ISSN:0003-6951    

DOI:10.1063/1.104068

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

In this letter, rapid thermal processing chemical vapor deposition has been used to grow high qualityinsitudoped silicon epitaxial layers. Device quality epilayers have been obtained for both boron and phosphorus doping with abrupt dopant transition profiles. The mobility values of these doped epilayers are very close to the values for bulk silicon under the same doping concentration.

ISSN:0003-6951    

DOI:10.1063/1.104069

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We have applied micro‐Raman spectroscopy to the analysis of structural quality of GaAs‐on‐Si where the GaAs growth was performed through openings in an amorphous mask. The presence of the symmetry forbidden transverse optic (TO) phonon band and line shape of the longitudinal optic (LO) phonon band have been used to extract information concerning the structural quality of microscopic regions of GaAs from the Raman spectra. The utility of TO to LO phonon intensity ratios as a measure of crystal quality has been corroborated by correlation to x‐ray rocking curve full width. The structural quality of selectively grown GaAs as determined from first‐order Raman ratios is found to degrade in the vicinity of the transition between single crystal and polycrystalline regions. This work also shows that post‐growth annealing significantly improves the quality of structures with minimum feature size as small as 2 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.104070

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A simple form for an implantation profile of monoenergetic, low‐energy (1–10 keV) positrons in solids is presented. Materials studied include aluminum, copper, molybdenum, palladium, and gold with atomic number ranging from 13 to 79. A simple set of parameters can describe the currently used Makhov profile in slow positron studies of solids. We provide curves and tables for the parameters that can be used to describe the implantation profiles of positrons in any material with atomic number in between 13 and 79.

ISSN:0003-6951    

DOI:10.1063/1.104071

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A cross‐slip mechanism, based on a commonly observed dislocation configuration and which can produce multiple misfit dislocations in the direction orthogonal to the initial slip direction, is put forth. The mechanism has eight crystallographic variants in (001) epitaxy, and is itself repeatable. The essence of the model is the configuration of the threading dislocation in the epilayer, which bends, avoiding an acute angle between the near‐surface screw segment and interfacial segment, resulting in a pinning point in the cross‐slip plane which is removed by some distance from the heterointerface.

ISSN:0003-6951    

DOI:10.1063/1.104072

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Influence of indium doping on the qualities of AlGaAs layers grown by molecular beam epitaxy has been studied. It was found that a proper amount of In doping can increase the photoluminescence intensity drastically by a factor greater than 10 indicating an improvement in the optical quality of AlGaAs epilayers. The improvement in the material quality is attributed to a higher surface migration rate of In atoms than those of Ga and Al atoms leading to a reduction of group III vacancies. However, too great a concentration of In atoms leads to effects that may degrade the film quality.

ISSN:0003-6951    

DOI:10.1063/1.104073

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

An influence of high‐dose &ggr; irradiation on the dependence of electron mobility on transverse electric field in the silicon surface inversion layer is experimentally determined and considered.

ISSN:0003-6951    

DOI:10.1063/1.104074

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A deep state possessing similar properties to those reported forDXcenters in the AlGaAs system has been observed at atmospheric pressure in GaSb moderately doped with sulfur. The first detailed deep level transient spectroscopy study of this material has revealed a large energy barrier to electron capture and a correspondingly small capture cross section for this deep level. The deep level activity of selenium‐ and tellurium‐doped GaSb has also been investigated.

ISSN:0003-6951    

DOI:10.1063/1.104075

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We report on the properties ofp‐type delta‐doped layers prepared in molecular beam epitaxy‐Si by growth interruption and evaporation of elemental B. Secondary‐ion mass spectrometry measurements at several primary ion energies have been used to show that the full width at half maximum is ∼2 nm. Hall measurements confirm that the layers are completely activated at 300 K with a mobility of 30±5 cm2/V s for a carrier density of (9±2)×1012cm−2. At temperatures below 70 K nonmetallic behavior is observed which we have attributed to conduction between impurity states. It is concluded that the critical acceptor separation for the Mott metal‐insulator transition in this system is significantly less than the value found in uniformly doped Si:B.

ISSN:0003-6951    

DOI:10.1063/1.104076

出版商:AIP    

年代:1990

数据来源: AIP