1. |
Attenuation ofcpropagating acoustic waves in CdS: Gru¨neisen parameter calculations |
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Applied Physics Letters,
Volume 24,
Issue 4,
1974,
Page 153-154
John H. Wasilik,
Fred S. Hickernell,
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摘要:
The room‐temperature attenuation for longitudinal acoustic waves propagating in thecdirection in high‐purity CdS has been measured from 0.1 to 0.6 GHz. At 0.5 GHz the attenuation is 46 dB/cm (tan&dgr;=0.0015). From the observed attenuation corrected for phonon‐electron contributions and a lattice loss theory of Woodruff and Ehrenreich, a Gru¨neisen parameter of ± 1.51 is calculated. An alternate method of calculating the Gru¨neisen parameter by using the pressure dependence of the elastic constants gives a Gru¨neisen parameter of ‐1.37.
ISSN:0003-6951
DOI:10.1063/1.1655131
出版商:AIP
年代:1974
数据来源: AIP
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2. |
rf‐sputtered aluminum nitride films on sapphire |
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Applied Physics Letters,
Volume 24,
Issue 4,
1974,
Page 155-156
A. J. Shuskus,
T. M. Reeder,
E. L. Paradis,
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摘要:
Single‐crystal films of aluminum nitride were fabricated on (0001)‐ and (011¯2)‐oriented sapphire substrates by reactive rf sputtering an aluminum target in ammonia gas. Films sputtered on either sapphire orientation were clear, smooth, and piezoelectric. Effective surface acoustic wave piezoelectric coupling constants as large ask2= 0.2% were found for films sputtered on (0001)‐oriented sapphire.
ISSN:0003-6951
DOI:10.1063/1.1655132
出版商:AIP
年代:1974
数据来源: AIP
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3. |
Circular stacking faults in silicon |
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Applied Physics Letters,
Volume 24,
Issue 4,
1974,
Page 157-158
W. K. Tice,
T. C. Huang,
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摘要:
An electron microscopic diffraction study for circular stacking faults in silicon has been carried out. For the first time it has been possible to make direct correlation between the faults and subsurface precipitates, and to confirm that circular fault growth involves climb of a Frank dislocation from a precipitate site.
ISSN:0003-6951
DOI:10.1063/1.1655133
出版商:AIP
年代:1974
数据来源: AIP
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4. |
Acousto‐optic deflection in Ta2O5waveguides |
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Applied Physics Letters,
Volume 24,
Issue 4,
1974,
Page 159-160
Douglas A. Wille,
Michael C. Hamilton,
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摘要:
Surface acoustic waves on quartz have been used for acousto‐optic deflection in Ta2O5waveguides. Deflection efficiencies for TM modes of up to 93% have been observed with an acoustic power of 175 mW.
ISSN:0003-6951
DOI:10.1063/1.1655134
出版商:AIP
年代:1974
数据来源: AIP
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5. |
dc effects in elastic surface waves |
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Applied Physics Letters,
Volume 24,
Issue 4,
1974,
Page 160-162
Yasuhiko Nakagawa,
Kazuhiko Yamanouchi,
Kimio Shibayama,
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摘要:
We report the observation of dc effects in elastic surface waves on 131° rotatedY‐cutX‐propagating LiNbO3. A simple model to account for these effects is suggested.
ISSN:0003-6951
DOI:10.1063/1.1655135
出版商:AIP
年代:1974
数据来源: AIP
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6. |
Acoustic microscope—scanning version |
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Applied Physics Letters,
Volume 24,
Issue 4,
1974,
Page 163-165
R. A. Lemons,
C. F. Quate,
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摘要:
This letter reports the development of a mechanically scanned acoustic microscope showing 10‐&mgr;m resolution. Using single‐surface lenses an acoustic beam is focused with negligible spherical aberration in a water cell. The image is formed by mechanically scanning an object through this focused beam in a raster pattern. Transmitted power is detected with a piezoelectric transducer, and this signal modulates the synchronized raster of a CRT display. By employing piezoelectric detection, sensitivities of 10−8W/cm2are obtained, yielding images of excellent clarity and contrast.
ISSN:0003-6951
DOI:10.1063/1.1655136
出版商:AIP
年代:1974
数据来源: AIP
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7. |
Bulk wave generation by surface interdigital transducers operating near resonance |
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Applied Physics Letters,
Volume 24,
Issue 4,
1974,
Page 165-167
P. J. Vella,
W. S. Goruk,
G. I. Stegeman,
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摘要:
The fraction of electrical power converted into spurious bulk waves at a surface interdigital transducer operating on and near surface wave resonance was measured. Bulk wave generation ony‐zlithium niobate was found to be strong below, at, and above resonance and to increase with decreasing number of finger pairs.
ISSN:0003-6951
DOI:10.1063/1.1655137
出版商:AIP
年代:1974
数据来源: AIP
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8. |
Schottky‐barrier solar‐cell calculations |
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Applied Physics Letters,
Volume 24,
Issue 4,
1974,
Page 167-169
D. L. Pulfrey,
R. F. McOuat,
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摘要:
Calculations are presented which indicate that the maximum theoretical solar conversion efficiency of Schottky‐barrier solar cells is very similar to that of conventional homojunction solar cells, e.g. values of 22–24% apply to Si, and ∼ 25% to semiconductors having a band gap between 1.4 and 1.6 eV.
ISSN:0003-6951
DOI:10.1063/1.1655138
出版商:AIP
年代:1974
数据来源: AIP
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9. |
Effect of refraction on spot‐size dependence of laser‐induced breakdown |
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Applied Physics Letters,
Volume 24,
Issue 4,
1974,
Page 169-172
M. D. Feit,
J. A. Fleck,
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摘要:
Detailed calculations have been performed to show the importance of refractive effects on laser‐induced breakdown in gases. The refraction, which results from gradients in the density of plasma electrons, can cause a loss of energy from the beam and an apparent dependence of breakdown threshold on beam or focal spot size.
ISSN:0003-6951
DOI:10.1063/1.1655139
出版商:AIP
年代:1974
数据来源: AIP
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10. |
Effect of inelastic energy loss on CO2laser breakdown of gases |
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Applied Physics Letters,
Volume 24,
Issue 4,
1974,
Page 173-175
M. P. Hacker,
D. R. Cohn,
R. L. Brooks,
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摘要:
The pressure dependence of the threshold energy for CO2laser gas breakdown in helium and nitrogen has been measured in the pressure range 40–70 Torr. The striking difference in the pressure dependence for the two gases is a clear manifestation of the effect of inelastic energy losses upon the avalanche breakdown process. This difference can be predicted by simple physical arguments or by scaling results from dc gas breakdown experiments to CO2frequency.
ISSN:0003-6951
DOI:10.1063/1.1655140
出版商:AIP
年代:1974
数据来源: AIP
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