摘要:

The third‐order optical nonlinearity &khgr;(3), linear absorption coefficient &agr;, and the two‐photon absorption coefficient &bgr; of two nickel dithiolene complexes are reported. The nonlinearities were measured at 1064 nm using 100 ps pulses. Molecular nonlinearities 103times those of carbon disulphide were observed. Two figures of merit were calculated from the data &Dgr;nsat/&agr;&lgr;=5 andn2/2&bgr;&lgr;≳2, where &agr; and &bgr; are the linear and two‐photon absorption coefficients andn2the nonlinear refractive index. These figures are compatible with those required for simple all‐optical switching devices.

ISSN:0003-6951    

DOI:10.1063/1.104969

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

A monolithic integration of a double barrier AlAs/GaAs resonant tunneling diode and a GaAs/AlGaAs quantum well laser is reported. Negative differential resistance and negative differential optical response are observed at room temperature. The device displays bistable electrical and optical characteristics which are voltage controlled. Operation as a two‐state optical memory is demonstrated.

ISSN:0003-6951    

DOI:10.1063/1.104970

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The transformation of nonplanar periodic laser array modes from weakly locked out‐of‐phase to locked in‐phase operation is investigated. A comparison study of near‐field and far‐field patterns is made for devices with differing mesa widths and heights. Data are presented which show that the mesa height and width can be adjusted to force in‐phase operation. An array of 19 elements shows an essentially single‐lobed far‐field pattern centered at 0° with full width at half maximum of 1.6°, to output powers of more than 500 mW/uncoated facet.

ISSN:0003-6951    

DOI:10.1063/1.104971

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

InSb films have been deposited directly by rf sputtering on sapphire substrates. X‐ray diffraction and scanning electron microscopy data are presented to show that the InSb layer on sapphire (0001) is epitaxial and grows with (111) parallel to the substrate surface. Optical absorption studies of the epitaxial film also reveal distinct spectral features which resemble these from bulk, single‐crystal InSb.

ISSN:0003-6951    

DOI:10.1063/1.104972

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Using a novel ball mill with controlled ball movement we have produced for the first time amorphous Fe50B50and Fe40B60alloys and nanocrystalline Fe80B20and Fe66B34alloys by mechanical alloying. The structural evolution of elemental powder mixtures is studied following milling and subsequent thermal treatment. Upon heating both amorphous and nanostructural mechanically alloyed Fe‐B alloys transform into a mixture of equilibrium phases.

ISSN:0003-6951    

DOI:10.1063/1.104974

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The microstructural variation of CoSi2buried layers formed by 100 keV Co+implantation at 350 °C into Si (111) is systematically studied. The critical dosedcof Co+implantation at 100 keV required to form a continuous CoSi2buried layer after annealing is the same in both Si (111) and (001), ≊1.1×1017cm−2, corresponding to a threshold peak concentration of 18.5 at. % Co. In addition, we observe continuous buried layers consisting of bothA‐(fully aligned) andB‐(twinned) CoSi2grains in the (111) samples implanted at doses ≊dc. The relative fractions ofAandBare found to vary with the implanted doses, current densities of the ion beam, and annealing conditions with theBfractions varying from 0% to 100%. ContinuousA‐type layers are formed only in the samples implanted to doses ≥1.6×1017cm−2.

ISSN:0003-6951    

DOI:10.1063/1.104947

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Amorphous ribbons of AlxDy100−x, 93≳x≳85, were obtained by melt spinning. During crystallization, in addition to Al, four different metastable crystalline phases of DyAl3were observed. These phases are, in order of appearance, the high‐pressure face‐centered cubic phase, &ggr;‐DyAl3and three polytypic rhombohedral phases, &bgr;‐DyAl3, &bgr;’‐DyAl3, and &agr;’‐DyAl3. It is the first time that the &bgr;’phase in rare‐earth trialuminides and the &agr;’phase in Dy‐Al alloy system have been observed. It is shown that all these phases are associated with the polytypic packing of the hexagonal DyAl3atomic layers. The relative stability of the phases is found to be related to the hexagonal to cubic stacking ratio in the structure.

ISSN:0003-6951    

DOI:10.1063/1.104948

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Complete selective epitaxy of GaAs by organometallic vapor phase epitaxy at atmospheric pressure was achieved by using TMG, AsH3, and AsCl3as starting gases. Selectivity was observed at growth temperatures ranging from 650 to 750 °C. The blocking of polycrystal deposition on the mask, Si3N4, or W, is attributed to the adsorption of HCl on the mask, thus preventing the nucleation of GaAs. On the openings, the growth rate may be adjusted by controlling the TMG/AsCl3ratio. When TMG/AsCl3<1, no growth occurs, but etching is observed.          

ISSN:0003-6951    

DOI:10.1063/1.104949

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We report on a detailed study of the influence of TiSi2silicidation on the formation of the quenched‐in defects usually created by rapid thermal processing (RTP). It is shown that TiSi2growth during RTP leads to a total removal of the defects, whereas the presence of TiSi2by itself (without growth) has no influence. It is concluded that the defect removal is caused by the strong vacancy injection induced by the silicide growth.

ISSN:0003-6951    

DOI:10.1063/1.104950

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The effects of hydrogen plasma exposure on the characteristics of ann‐channel metal‐oxide‐semiconductor field‐effect transitor are studied. The helium plasma gives almost no changes in maximum transonductance and subthreshold slope whereas the hydrogen plasma degrades maximum transconductance and increases subthreshold slope. These results indicate that the excess interface traps are generated by hydrogenation, which is also confirmed by quasi‐static capacitance‐voltage analysis.

ISSN:0003-6951    

DOI:10.1063/1.104951

出版商:AIP    

年代:1991

数据来源: AIP