摘要:

Peltier‐induced liquid‐phase epitaxial growth of Ga1−xAlxAs (0.1⩽x⩽0.3) was carried out at constant temperature with the dc as the sole driving force and controlling element of the growth. Electric currents of 10–30 A/cm2were passed through the solid‐liquid (S‐L) interface (which acts as a Peltier junction) thereby cooling this interface and causing growth. The growth rate is linearly proportional to the current level. GaAlAs layers of 15–58 &mgr;m thickness were grown from relatively small melts (∼5 g) at several temperatures in the range 600–850 °C. Photoluminescence microanalysis of the layers showed that the aluminum composition was remarkably uniform throughout the total layer thickness. In all cases, the variation of the aluminum concentration (x) was observed to be ±0.005 or less.

ISSN:0003-6951    

DOI:10.1063/1.88497

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

Surface‐acoustic‐wave correlation of two signals has been performed by using space‐charge nonlinearity in a layered structure of Bi12GeO20‐Si‐LiNbO3. The two surface waves are collinear and propagate in the same direction. The same structure has also been used in a different mode of operation to perform the functions of convolution and time scaling.

ISSN:0003-6951    

DOI:10.1063/1.88498

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

A relativistic self‐consistent equilibrium is found for the magnetic insulation of a diode for conditions where the voltage rise time is long compared to the cyclotron period. Instability of the magnetic insulation equilibrium may allow high‐power pulsed microwave generation in magnetronlike configurations.

ISSN:0003-6951    

DOI:10.1063/1.88499

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

Theoretical arguments are presented which show that electronic space charge can transfer large amounts of energy to ions while simultaneously focusing and bunching their arrival at a small pellet.

ISSN:0003-6951    

DOI:10.1063/1.88500

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

Subpicosecond time resolution with a new design of the electron‐optical streak camera (the Photochron II) is demonstrated with ultrashort Raman pulses.

ISSN:0003-6951    

DOI:10.1063/1.88501

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

We briefly describe the method and communicate the results of a number of calculations concerning the shock vaporization of different metals which are of practical interest for atmospheric and ionospheric vapor releases (Li, Na, Sr, Ba, Pb, Eu, Fe, and U). The calculations include the determination of shock‐wave entropies and residual temperatures, as well as a model description of the vaporization process upon expansion of the released material into vacuum. The results contain explicit values for the degree of vaporization from the onset up to conditions corresponding to critical entropy, depending upon shock strength.

ISSN:0003-6951    

DOI:10.1063/1.88502

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

A survey of the experimental energy loss of4He ions shows systematic differences between elemental solids and gases. The solid‐gas differences are proposed as an empirical first‐order correction to obtain solid‐target values from gas‐target stopping cross sections. These corrections are of the order of 20% for4He ions of 1 MeV. A series of experiments on the energy loss of4He ions in oxygen and nitrogen in solid oxides and nitrides are in agreement with the empirical correction factor proposed.

ISSN:0003-6951    

DOI:10.1063/1.88503

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

Phase matching for frequency tripling of 1.06 &mgr;m is demonstrated in a homogeneous mixture of sodium and magnesium vapor. For phase matching, the ratio of Mg to Na vapor pressures is 2 : 1. This ratio is about 1/75 of the ratio of Xe to Na required for phase matching.

ISSN:0003-6951    

DOI:10.1063/1.88504

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

Optical behavior of isoelectronic impurities in AlxGa1−xAs (x=0.37) is investigated. Photoluminescence of the samples implanted with N was measured at 2 °K. A new luminescence line is observed at an energy which is 90 meV below the edge emission peak. The integrated intensity of the N‐implanted sample is about five times larger than that of an unimplanted and annealed sample. This is thought to be due to the bound states produced by the N atoms which replace the As atoms.

ISSN:0003-6951    

DOI:10.1063/1.88505

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

Addition of a fluorescent dye to the liquid used for scattering particle production in a laser Doppler velocimeter can result in a number of practical advantages. An investigation of this concept has been carried out using various dyes and solvents to determine its potential and limitations. The term ’’fringe mode fluorescence velocimetry’’ is recommended to describe this technique.

ISSN:0003-6951    

DOI:10.1063/1.88506

出版商:AIP    

年代:1975

数据来源: AIP