摘要:

Isopropyl ammonium chloroplatinate (C3H7NH3)2PtCl6and the corresponding chlorostannate (C3H7NH3)2SnCl6are demonstrated to be ferroelastic by observation of the stress‐induced motion of (100) and (001) shear domain walls. The ferroelastic transition temperatures are at 37 and 40 °C, respectively, at room pressure and increase approximately linearly with increasing hydrostatic pressure. X‐ray structure analysis and the absence of measurable second‐harmonic generation (SHG) in either higher‐ or lower‐temperature phases suggest that these crystals belong to the Aizu ferroelastic speciesmmmF2/m.

ISSN:0003-6951    

DOI:10.1063/1.1654824

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Room‐temperature cw operation is reported for an acoustic surface wave amplifier which uses a 25‐&mgr;m‐wide thin film of InSb deposited on LiNbO3. The device also illustrates the use of a thin semiconductor or metal film as a waveguiding structure which exhibits very little dispersion. A cw gain of 23 dB was observed at 340 MHz with a group delay factor (1/&tgr;)∂&tgr;/∂f= −8.3 × 10−7MHz−1.

ISSN:0003-6951    

DOI:10.1063/1.1654825

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

AnLClattice with nearest‐ and second‐neighbor inductive coupling between the capacitors is described and shown to exhibit linear wave transformation properties when the capacitor values vary iteratively down the lattice structure. Possible applications as a device for selectively delaying, transmitting, or storing pulses of slightly differing frequencies are suggested.

ISSN:0003-6951    

DOI:10.1063/1.1654826

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The well‐known similarity principles for dc breakdown in gases are extended to the case of laser‐induced breakdown. The wealth of experimental data on kinetic processes in gases may therefore be directly applied to ac breakdown. Without solving the Boltzmann equation, the ionization rate is determined as a function of pressure, frequency, electric field, etc. This has important implications for the maximum possible light intensity in high‐pressure TEA amplifiers.

ISSN:0003-6951    

DOI:10.1063/1.1654827

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Electric field enhancement of photoemission from negative‐electron‐affinity surfaces on silicon and GaAs has been studied. It is shown that the electric field increases the escape probability and does not change the spectral response of negative‐electron‐affinity surfaces. The results are explained by assuming a simple surface potential barrier together with work function lowering by the Schottky effect.

ISSN:0003-6951    

DOI:10.1063/1.1654828

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Electron injection into a highly permeable spherical anode under high‐vacuum conditions has been observed to produce a negative well within the anode. When deuterium gas is introduced into the system, experimental observations strongly suggest that a positive potential region is formed within the negative potential well, which gives rise to a multiple potential well structure within the anode.

ISSN:0003-6951    

DOI:10.1063/1.1654829

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A new class of intermediate‐gain laser materials for rare‐earth ions, based upon the principle of inhomogeneous broadening of spectral lines in mixed‐compound crystals, is reported. Spectroscopic evidence for Nd in YAl0.6Ga0.4G mixed garnets is presented which shows a cross‐section reduction of 3.3 compared to Nd in YAlG. Other physical properties of the mixed garnets, in particular the thermal conductivity, are not degraded; consequently, the Nd‐doped mixed garnet materials may prove important for increased‐energy/pulse high‐average‐powerQ‐switched laser applications.

ISSN:0003-6951    

DOI:10.1063/1.1654830

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The voltage‐current dependence is investigated for pulsed self‐sustained uniform‐glow discharges by using commerical‐grade mixtures of CO2, N2, and He at near‐atmospheric pressures. For a given mixture, the discharge is found to stablize at a value ofE/Nwhich is independent of discharge current density, total pressure, and electrode spacing;Eis the electric field andNis the number density of the gas. We interpret these observations as evidence that the glow condition is effectively controlled by attachment to CO2and also to H2O, a gaseous impurity. Calculations of theE/Ncharacteristic, based on a model which includes recombination and attachment losses, are in agreement with experimental results for all mixtures studied.

ISSN:0003-6951    

DOI:10.1063/1.1654831

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

It is shown that in predicting the temperature dependence of multiphonon absorption one must take the temperature dependence of the phonon frequencies into account. Inclusion of the latter leads to results in improved agreement with experiment, as compared to those of Hardy and Agrawal.

ISSN:0003-6951    

DOI:10.1063/1.1654832

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The threshold for laser‐induced breakdown has been found to be influenced by an electric field transverse to the laser focus. In air at a pressure of 20 Torr a field strength of 600 V/cm was found to completely suppress breakdown. At higher field strengths the electric field was found to induce breakdown rather than suppress it. These effects are explained as being due to charge removal and electron cascade.

ISSN:0003-6951    

DOI:10.1063/1.1654833

出版商:AIP    

年代:1973

数据来源: AIP