摘要:

Light diffracted from a grating output coupler in a Ti‐diffused LiNbO3waveguide is scanned electro‐optically. Using a coupling length of 2.5 mm in our arrangement we have demonstrated a scanning capability of one resolved spot per 3 V/&mgr;m applied field.

ISSN:0003-6951    

DOI:10.1063/1.89849

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

It is proved that the three diffusion coefficients, related to noise, spreading of a bunch of carriers, and gradient of concentration, are identical. This demonstrates in the hot carrier regime the validity of the relationkTn(E)/q=D(E)(dvd(E)/dE)−1which is an extension of the Ohmic Einstein relation (Tnis the noise temperature,Dis the diffusion coefficient,vdis the drift velocity). Therefore the noise and time‐of‐flight techniques appear as being two ways which are quite different, leading to the same diffusion coefficient.

ISSN:0003-6951    

DOI:10.1063/1.89850

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The experiments on the stability of small bits in amorphous GdCo thin films under changes of the external magnetic field and the temperature were performed. It is concluded that the bits written in films which are inhomogeneous along the film thickness are stable. No deterioration for the thermomagnetic and magneto‐optic application could be found in these films.

ISSN:0003-6951    

DOI:10.1063/1.89851

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A conformal antireflective coating of WO3on a textured tungsten surface is found to significantly increase the optical absorptance of the surface over a broad selected band of wavelengths. The coating enhances the selectivity of solar absorbing surfaces on dendritic tungsten and increases the solar absorptance of such surfaces. The average solar absorptance measured at air mass 2 was increased from 0.95 to 0.985 for large dendrite surfaces and from 0.76 to 0.90 for small dendrite surfaces. Emittance values for the anodized surfaces at 300 °C range from 0.18 for the small dendrites to 0.5 for the larger dendrites. The WO3conformal coating, produced by anodization of the tungsten, forms an antireflective coating with a minimum at a wavelength between 0.43 and 0.8 &mgr; for anodization voltages between 20 and 40 V, respectively. Total reflectances as low as 0.00025 have been measured.

ISSN:0003-6951    

DOI:10.1063/1.89852

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Metal‐insulator‐semiconductor capacitors were prepared by doping an Al0.5Ga0.5As layer with oxygen in order to demonstrate a lattice‐matched single‐crystal insulator‐semiconductor heterojunction. Crystal growth was by molecular‐beam epitaxy. Interface trap effects were not observed in capacitance‐voltage measurements, while the current‐voltage measurements show space‐charge‐limited currents for forward and reverse biases.

ISSN:0003-6951    

DOI:10.1063/1.89853

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Simple analytic procedures are given for finding the Fermi energy in a semiconductor with a parabolic or nonparabolic band structure, and (Al,Ga)As is treated as an example of a nonparabolic material in which each of the three conduction bands, &Ggr;,L, andX, competes effectively for electrons. The electron and hole Fermi energies form the basis for determining the voltage and further electrical characteristics of a semiconductor device.

ISSN:0003-6951    

DOI:10.1063/1.89854

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Measurements of the subthreshold velocity‐field characteristic at 77 K using a direct technique show reasonable agreement with theoretical predictions, but show a lower threshold field. Comparisons of threshold values of field and velocity with extrapolations from other measured and theoretical data are favorable.

ISSN:0003-6951    

DOI:10.1063/1.89855

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Si layers deposited on Au‐Si substrates at temperatures above 380 °C are epitaxial with the underlying Si substrate. The layers analyzed contain a high density of microtwins which is the main factor resulting in dechanneling in the aligned RBS spectrum. The deposited layers also contain stacking faults and residual Au inclusions adjacent to primary twins.

ISSN:0003-6951    

DOI:10.1063/1.89856

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Compressive stresses arising from differential contraction of the bronze matrix were found to cause an increase in the critical temperature,Tc, of bronze‐processed V3Ge. This unusual behavior for anA‐15 compound is in qualitative agreement with Testardi’s theory, although the enhancement ofTcdoes not increase parabolically with strain and saturates at strains of ∼0.5%.

ISSN:0003-6951    

DOI:10.1063/1.89857

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Lorentz microscopy and magnetization and Mo¨ssbauer effect measurements have been performed on a Cr‐Co‐Fe alloy having a two‐phase microstructure. Domains spanning many particles have been seen in samples whoseHc’s vary between 200 and 420 Oe. Walls appear to be ragged and are held back by particles. Magnetization and Mo¨ssbauer effect measurements indicate that the two phases constituting the microstructure in each of the three situations examined are ferromagnetic at ambient temperature. Based on these results it is inferred that domain‐wall–particle interaction is responsible forHc.

ISSN:0003-6951    

DOI:10.1063/1.89858

出版商:AIP    

年代:1978

数据来源: AIP