摘要:

A method is presented which makes possible the determination of the critical resolved shear stress, &tgr;c, for dislocation movement in a crystal. The method is based on the analysis of dislocation rosettes which are generated either by microindentation, or by precipitates of a second phase. The method does not require a knowledge of the indentation (or precipitate) stress field; it requires only information on the positions of a set of leading dislocation loops. At once one can also obtain theeffectiveindentation stress field and, for the first time, the precipitate stress field. For illustration, the method is applied to the determination of &tgr;cin silicon, using both indentation and precipitate dislocation rosettes. The value of &tgr;cthus obtained varies from a low of 3×107dyn/cm2in oxygen‐free samples to a high of 5.5×108dyn/cm2in a sample containing ∼2×1018atoms/cm3of oxygen with clustering. The SiO2precipitate stress field in the present case was found to vary asx−1, suggesting that the precipitate is probably a thin plate.

ISSN:0003-6951    

DOI:10.1063/1.89629

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Two EPR spectra are resolved in quenched silicon; one is attributed to a surface damage formed during the quench and the other to the interstitial iron (Fe0) previously identified by Woodbury and Ludwig in Fe‐diffused silicon. The enthalpy and entropy for the Fe0formation are determined to be 2.39 (±0.03) eV and 3.3 (±0.3) K, respectively. The migration energy of Fe0is 0.69 (±0.03) eV. The transition‐metal ion is present in as‐grown silicon and moves to theTdinterstitial site upon heat treatment.

ISSN:0003-6951    

DOI:10.1063/1.89630

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

We have devised a simple acoustic focusing device with an interdigital transducer in which all radiation from each section of the transducer constructively interferes at a focal point in water. The device is applicable to the acoustic imaging in both transmitting and reflecting modes.

ISSN:0003-6951    

DOI:10.1063/1.89631

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

For the first time a surface acoustic waveguide has been made by diffusing titanium intoyz‐LiNbO3to serve as the fast cladding region. The guides are excited by transducers operating at 240 MHz and exhibit low loss. Dispersion characteristics presented illustrate the effects of lateral confinement.

ISSN:0003-6951    

DOI:10.1063/1.89632

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

When CO2‐laser pulses of ∼50 ns duration and intensity of ∼100–500 MW/cm2are incident upon NixP1−xsurfaces in oxygen‐containing atmospheres, distinctive ’’ripple’’ patterns are etched into the surfaces. The ripple wave fronts are normal to theEfield and vary in spacing from ∼&lgr;laserat normal incidence to ∼0.5&lgr;laserfor &pgr; polarization at grazing incidence.

ISSN:0003-6951    

DOI:10.1063/1.89633

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

It is demonstrated that electron‐beam collapse in a diode using a thin foil anode takes place considerably faster than in a diode using a thick anode. The effect is shown to follow from earlier ion emission from a thin anode as well as from the different nature of the electron trajectories in that case. Applications for pellet fusion and for obtaining very high energy densities in matter are suggested.

ISSN:0003-6951    

DOI:10.1063/1.89634

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

The ion beam current from a multidipole source can be increased by the injection of low‐energy primary electrons. By optimizing the injection energy, an increase in beam current of approximately 35% has been achieved.

ISSN:0003-6951    

DOI:10.1063/1.89635

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

The rate of interlayer diffusion during annealing of InSb/GaSb superlattice structures with layer thicknesses ranging from 12.5 to 50 A˚ has been investigated. The films were grown by multitarget rf sputtering on InSb‐coated Corning 7059 glass slides. The InSb underlayers were deposited at 320 °C and were approximately 300 A˚ thick. The multilayer films had a total thickness of ∼1 &mgr;m and were grown at either 200 or 250 °C in an Ar sputtering pressure of 15 mTorr (2 Pa). Prior to annealing the samples were encapsulated in a 1000‐A˚‐thick rf sputtered overlayer of In2O3. InSb/GaSb interlayer diffusion was investigated using x‐ray diffraction techniques in which the intensity of satellite peaks around the Bragg reflection peaks were monitored as a function of annealing time. A diffusion coefficient of 4.5×10−21cm2/sec was determined for an annealing temperature of 320 °C.

ISSN:0003-6951    

DOI:10.1063/1.89636

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

A double‐layered encapsulation consisting of a 1000‐A˚ plasma‐deposited Si3N4layer under a 3000‐A˚ CVD SiO2layer doped with arsenic has been used to anneal selenium ion‐implanted GaAs at temperatures up to 1100 °C with no signs of mechanical failure when examined with a scanning electron microscope. Significant improvement in electrical activation of implanted layers over simple Si3N4layer caps has also been observed at lower temperatures.

ISSN:0003-6951    

DOI:10.1063/1.89623

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

A novel inorganic electron resist is proposed. It is shown that the electron irradiation on a stacked layer composed of a thin Ag film over a layer of Se‐Ge chalcogenide amorphous glass enhances diffusion of Ag into Se‐Ge glass, in the same manner as in the case of photodoping. The Ag‐doped Se‐Ge film becomes almost insoluble in alkaline solutions. A negative‐type electron resist is realized by applying this effect. This inorganic electron resist is proved to exhibit an extremely high contrast (&ggr;∼8). The sensitivity is 4×10−5C/cm2at 5 kV. It is confirmed that fine‐pattern delineation of less than 0.3 &mgr;m linewidth is possible.

ISSN:0003-6951    

DOI:10.1063/1.89624

出版商:AIP    

年代:1977

数据来源: AIP