摘要:

Computations of the variation with groove depth of the SAW scattering properties of a uniform shallow‐grooved reflector array are reported for an equivalent isotropic elastic substrate representingY‐cutZ‐propagating LiNbO3. In agreement with previous qualitative conclusions based on experimental studies of SAW grooved resonators, the present computations indicate the existence of an optimum groove depth yielding maximum array SAW reflectivity. This optimum groove depth is a monotonically decreasing function of the total numberNof grooves in the array. Computed optimum groove depths for various fixed values ofNare presented.

ISSN:0003-6951    

DOI:10.1063/1.89930

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Recent advances in the field of acoustic microscopy have allowed the instrument to be operated at wavelengths that correspond to the center of the optical band. Experimental results in the form of acoustic micrographs are presented and compared to their optical counterparts. It is apparent that the resolving power of the instrument is similar to that of the optical microscope. Also it is seen that the acoustic micrographs yield information on the subsurface region. This information is not available in the optical images.

ISSN:0003-6951    

DOI:10.1063/1.89931

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Electron neutralization is a key feature in the propagation of intense ion beams. A one‐dimensional sheath solution is given that demonstrates how electrons are captured by a transient ion beam emerging into a field‐free vacuum. Conditions for space‐charge and current neutralization are discussed. The importance of the electron distribution in determining the minimum spot size of a focused ion beam is considered.

ISSN:0003-6951    

DOI:10.1063/1.89932

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Surface‐potential decay in naphthalene single crystals was measured after a negative corona discharge on the samples. These potential decay curves do not reach zero value, which is attributed to charges which have been trapped on their way through the sample. The value found for the trap‐modulated mobility at room temperature was 10−8cm2 V−1 s−1and its dependence on temperature was adequately described by an Arrhenius equation, with activation energy of (0.60±0.03) eV.

ISSN:0003-6951    

DOI:10.1063/1.89933

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The suppression of stimulated Brillouin scattering by Faraday rotation in a laser‐heated solenoid is examined. Theory and experimental results are compared.

ISSN:0003-6951    

DOI:10.1063/1.89934

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Coatings for efficient photothermal conversion of solar energy should have high absorption at wavelengths &lgr;<&lgr;cand low absorption at &lgr;≳&lgr;c, where &lgr;cis ∼2 &mgr;m. For granular metals, we show by computation that &lgr;cdepends strongly on the shape of the metal particles. Increasing eccentricity of ellipsoidal grains is seen to displace &lgr;ctowards the infrared. A similar shift is found also for spherical metallic shells surrounding dielectric cores of increasing size. Some implications for practical absorber surfaces are pointed out.

ISSN:0003-6951    

DOI:10.1063/1.89935

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The lattice contraction in boron‐implanted laser‐annealed silicon has been studied by x‐ray Bragg reflection profiles and ion channeling. The contraction was shown to be one dimensional, along the surface normal, for strains as large as 1.3%.

ISSN:0003-6951    

DOI:10.1063/1.89936

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A composite PMMA resist is described with a linear sensitivity of 10−10C/cm for a 0.8‐&mgr;m resist thickness. It uses a simple one‐step development process, gives a pronounced undercut profile suitable for metal lift‐off, and to date has allowed interline spacings of 1.5 &mgr;m in 0.4‐&mgr;m‐thick resist. Some development and exposure characteristics are described.

ISSN:0003-6951    

DOI:10.1063/1.89937

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The integration of an injection semiconductor laser with an active electronic device (Gunn oscillator) in asingleepitaxial crystal device is demonstrated.

ISSN:0003-6951    

DOI:10.1063/1.89922

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Low‐resistivity ZnxCd1−xS films have been obtained by a multisource evaporation method. The films have been doped with In during the deposition. The resistivity of such films varies from 2×10−3&OHgr; cm forx=0 up to 2 &OHgr; cm forx=0.3 and rises up to 1012&OHgr; cm forx=1. For energies lower than the energy gap, the transparency of these films, when corrected for the reflection loss, can reach a value of almost 100%. In the range of anxvariation between 0 and 0.4 these films, because of their low resistivity and their high transparency, can be used as windows in heterojunction solar cells.

ISSN:0003-6951    

DOI:10.1063/1.89923

出版商:AIP    

年代:1978

数据来源: AIP