摘要:

A superconducting tunnel junction was bombarded with alpha particles and the resulting pulses in the quasiparticle tunneling current were observed. The possibility of utilizing this effect in nuclear spectrometry is discussed.

ISSN:0003-6951    

DOI:10.1063/1.1652983

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Data describing the piezoelectric coupling to surface waves in &agr;‐quartz, PZT‐4, and LiNbO3are given.

ISSN:0003-6951    

DOI:10.1063/1.1652984

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

In this letter we report the observation of the Gunn effect inn‐type InSb at 77°K and atmospheric pressure. This result is surprising, since it was previously thought that the large amount of carrier multiplication at fields below the Gunn threshold would preclude observation of the Gunn effect in InSb and similar materials. Several explanations for the negative differential conductivity underlying the Gunn effect in this case are possible, but the intervalley transfer mechanism is most consistent with the observed negative pressure coefficient of the threshold field.

ISSN:0003-6951    

DOI:10.1063/1.1652985

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Boron was predeposited in silicon substrates by conventional diffusion techniques and then redistributed by bombarding the substrates with 10‐ and 50‐keV protons. The substrates were held at a fixed temperature in the range 500 to 700°C for the duration of the bombardment. The resulting impurity profiles were determined. The low‐energy impurity profiles are characterized by very abrupt junctions while the high‐energy impurity profiles are characterized by long tails. No variation of either the 10‐ or the 50‐keV impurity profiles with temperature was seen over the range given above.

ISSN:0003-6951    

DOI:10.1063/1.1652986

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

A method is described for recording channeling patterns by autoradiographic display of the distribution of the deeply penetrating fraction of Kr‐85 ions injected into single‐crystal surfaces at various angles with respect to the channeling direction. Using this method, channeling widths were measured for the penetration of low‐energy (3 to 10 keV) Kr ions into Si and compared with predicted critical channeling widths.

ISSN:0003-6951    

DOI:10.1063/1.1652987

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Theoretical limitations of optical heterodyne detection with pyroelectric detectors are discussed. It is shown that the minimum detectable powerPmof Sr1−xBaxNb2O6pyroelectric detectors at 10.6&mgr;, with an intermediate frequency of 1 MHz and a local oscillator powerPL= 1 W isPm= 8×10−16W/Hz. An experimental heterodyne receiver with the above conditions is shown to have a valuePm= 1.5×10−11W/Hz where amplifier noise is much larger than detector noise. The theoretical and experimental dependence ofPmonPLare compared in the amplifier noise limit.

ISSN:0003-6951    

DOI:10.1063/1.1652988

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

An Auger electron spectrometer for studies of solid surfaces which is considerably more sensitive than currently used instruments has been developed. The greatly improved signal‐to‐noise ratio of the spectrometer made it possible to display the 0–1000 eV Auger spectrum on an oscilloscope at a scanning rate of 20 000 V/sec. Alternatively, the scanning rate may be reduced to that typical of present instruments (∼2 V/sec) and the primary beam current reduced from 5 × 10−5to 10−8A.

ISSN:0003-6951    

DOI:10.1063/1.1652989

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Sputtered films of ferroelectric Bi4Ti3O12have been prepared by using targets containing excess Bi to compensate for loss of Bi in the deposition process. Epitaxial growth has been achieved on MgO and epitaxial Pt substrates. Studies of dielectric properties suggest that the sputtered films are suitable for use in high‐capacitance structures. Hysteresis measurements yield spontaneous polarization values for the epitaxial films which are in excellent agreement with those reported for bulk single crystals.

ISSN:0003-6951    

DOI:10.1063/1.1652990

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Instantaneous display of diffracted beams and their rapid photographic recording are achieved through use of a 4‐stage light image intensifier (EMI 9694). Beams carrying only 10 x‐ray photons sec−1mm−2are clearly seen on intensifier output phosphor by the naked eye. With an x‐ray tube of 800‐W power only and total experiment time less than a minute x‐ray projection topographs revealing individual crystal lattice dislocations are obtained by photographing a television display of intensifier output phosphor.

ISSN:0003-6951    

DOI:10.1063/1.1652991

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

A method of determining the purity of CdTe which may also be applicable to other compound semi‐conductors is presented. The electrical conductivity of undoped and lightly doped CdTe was studied from 600 to 900°C as a function of the partial pressures of its components. At high tellurium over‐pressures the conductivity is independent of partial pressure. The conductivity of undoped material depends exponentially upon temperature with an activation energy characteristic of intrinsic conduction. For indium‐doped CdTe and for material containing impurities the intrinsic conductivity levels off with a reduction in temperature and becomes characteristic of the foreign atom concentration.

ISSN:0003-6951    

DOI:10.1063/1.1652992

出版商:AIP    

年代:1969

数据来源: AIP