摘要:

Amorphous layers of Si produced by the bombardment of Sb+and In+and covered with ∼400 Å of Al show pronounced migration of the implanted atoms to the Si&sngbnd;Al interface and the Al surface after a 350°C anneal. This enhanced migration occurs simultaneously with the recrystallization of the amorphous layer. Low‐temperature migration effects are not seen in uncoated amorphous Si, nor on reordered Si covered with evaporated Al. The depth distribution of the implanted atoms is measured by backscattering analysis with 280‐keV &agr; particles.

ISSN:0003-6951    

DOI:10.1063/1.1654053

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Laser action has been achieved in six hydrogen and deuterium halides formed in chemical reactions initiated by a pulsed transverse discharge. A total of 246 wavelengths from 2.6 to 19.7 &mgr;m was observed. Nearly 30% of these transitions have not been previously observed in laser action. All of the lasers operate at relatively high pressure and promise to give very‐high‐power outputs.

ISSN:0003-6951    

DOI:10.1063/1.1654054

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

We have demonstrated that fixation and erasure of phase holograms in ferroelectric materials can be achieved by fast electrical control. High ionic mobility that allows the change of the electronic pattern into a stable ionic one is obtained by applying, during 0.1 sec, an external field slightly smaller than the coercive field to the crystal. Erasure is accomplished in 3 sec by applying a field that causes saturation of the polarization. Investigation of this process was carried out in BaTio3crystals doped with Fe.

ISSN:0003-6951    

DOI:10.1063/1.1654055

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Lithium precipitation in Czochralski‐grown germanium crystals is investigated by x‐ray transmission topography. Precipitation on dislocations is detected. Striated distributions of precipitates in dislocation‐free crystals are attributed to lithium nucleation on vacancy clusters.

ISSN:0003-6951    

DOI:10.1063/1.1654056

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Direct optical triggering of an avalanche transistor with a short laser pulse has been demonstrated. In some applications this system provides a compact low‐jitter replacement for a laser‐triggered spark gap. The technique has been applied to generating the gating and sweep voltages in a picosecond streak camera for laser pulse diagnostics where it eliminates the need for multiple beam splitters and long delays. The ``trigger'' avalanche transistor was placed as one of a series string of avalanche transistors. A portion of the switched‐out laser pulse to be diagnosed was focused onto the trigger transistor chip. Nanosecond‐rise kilovolt waveforms are thus generated with time jitter of the entire system being less than 100 psec.

ISSN:0003-6951    

DOI:10.1063/1.1654057

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Several compositions of InxGa1−xAs have been operated as optically pumped lasers at room temperature. Coherent emission has been observed out to 1.12 &mgr;m, corresponding to an alloy composition ofx≃ 0.20. Typical total‐power‐conversion efficiencies are measured to be 0.6%.

ISSN:0003-6951    

DOI:10.1063/1.1654058

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The effects of neutron irradiation on silicon carbide light‐emitting diodes (LED's) have been studied over the temperature range 76–300°K. The results indicate that over the entire temperature range the radiative current in the low‐voltage region is due to tunneling and subsequent radiative recombination in the depletion layer. Since this type of current is fairly radiation resistant, it is suggested that the SiC LED is an attractive device for operation in a neutron environment.

ISSN:0003-6951    

DOI:10.1063/1.1654059

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Ion‐implantation damage has been studied in thin reeds of silicon by resonant‐frequency and internal‐friction measurements. For a dose of 1016/cm2of28Si+, the principal effects are the appearance of an internal‐friction peak and a decrease in the flexural vibration frequencies. The amorphous surface layer produced by implantation is deduced to have a Young's modulus of 1.24×1012dyn/cm2and a density of 0.95 of the crystal density. The internal stress in the amorphous layer has been measured and found to be far smaller than that corresponding to a purely elastic accommodation of the density change.

ISSN:0003-6951    

DOI:10.1063/1.1654060

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Depth and temperature dependences of ion channeling were used to characterize 1–4‐&mgr;m Si layers on spinel substrates (Al2O3· MgO). Profiles of the density of crystal imperfections in the Si layers have been calculated from the channeling spectra. The imperfections are greatest near the interface, and the crystalline quality improves significantly with increasing distance from the interface. This technique is particularly applicable to heteroepitaxial layers containing high densities of crystal imperfections and can be used to monitor the relative influence of growth parameters on the crystalline quality of the layers.

ISSN:0003-6951    

DOI:10.1063/1.1654061

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Transport properties of sputtered VO2films are shown to be critically dependent on the defect structure of this material. Measured values of thermoelectric power and Hall mobility for films deposited under optimum conditions are comparable to those previously measured on single crystals.

ISSN:0003-6951    

DOI:10.1063/1.1654062

出版商:AIP    

年代:1972

数据来源: AIP