摘要:

Internal friction measurements made as a function of strain amplitude on deformed sodium chloride single crystals were followed by elastic modulus measurements made during x irradiation of the same crystals. Etch pit densities were also determined. These data were used to evaluate the constants in a theory, proposed by Granato and Lu¨cke in 1956, which permits the calculation of the average length of the dislocation segments,L, which vibrate under an applied alternating stress. An independent determination of the magnitude ofLwas made from the elastic modulus data using a method developed by Gordon and Nowick.It is concluded that the theories tested in this paper give a useful representation of dislocation damping phenomena in sodium chloride and permit use of internal friction measurements for the continuous observation of dislocations.

ISSN:0021-8979    

DOI:10.1063/1.1735780

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

A theory is developed for the spectrum of electrical noise due to electron transitions between several quasi‐isolated groups of states, in the general case where each group may carry part of an electric current. It is applied to the noise due to transitions between valleys of the conduction band of germanium, and the possibility of observing this noise is discussed using the data of Weinreich, Sanders, and White on the frequency of intervalley transitions.

ISSN:0021-8979    

DOI:10.1063/1.1735782

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

An analysis is given on the influence of bulk recombination within the base region of a mesa‐type drift transistor. The minority carrier transport efficiency is established for a solid cylinder base region and also for a simplified one‐dimensional structure. A comparison of the two minority carrier transport equations shows the approximate analysis will result in a negligible error when applied to practical semiconductor devices.

ISSN:0021-8979    

DOI:10.1063/1.1735783

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

Several analyses of the transport of cathode shot noise through a space‐charge‐limited diode at microwave frequencies have been published to date. Each of these analyses has been beset by inconsistencies arising from assumptions of monovelocity perturbation flow, direct or reflected. A new method of analysis of diode flow eliminating this problem has been developed. Numerical results based on this method are presented here. Attention is restricted to the now classical problem of one‐dimensional longitudinal confined flow.The magnitude and variation with distance of the so‐called beam noise invariants is shown for a range of diode operating conditions. These calculated results, based for economy on an approximate static flow model, essentially substantiate the qualitative expectations suggested by prior analyses, and fit what little experimental data are available.The method of analysis employed in the calculation of the numerical results comprises a linear multistream formulation, based on representation or approximation of the perturbation particle density for the noise flow as a composite of singular impulse streams,Nin number, along characteristic trajectories in the velocity‐distance phase space. The set ofNcoupled first‐order linear differential equations resulting is solved by simultaneous numerical extrapolation.

ISSN:0021-8979    

DOI:10.1063/1.1735784

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

The equations describing the flow of a power‐law non‐Newtonian fluid on a rotating disk have been solved in general form. This makes it possible to calculate how the shape of an initial surface contour will vary with time and to investigate the possibility of producing uniform films by applying the materials to a rapidly spinning disk. It is shown that the latter process, which has potential industrial applications, has a much better chance of succeeding if the fluid is Newtonian than if it is not, in the sense that whereas for a Newtonian substance centrifugation will smooth out irregularities in the surface contour, for a non‐Newtonian fluid even an initially uniform film thickness will be deformed by rotating the plate.

ISSN:0021-8979    

DOI:10.1063/1.1735785

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

A study has been made of the photovoltaic effect in Cu&sngbnd;CdS cells and related systems, associated with undiffused metal‐semiconductor junctions. The photovoltaic current has been shown to result from the photoemission of electrons from the copper metal into the CdS crystal. Direct evidence is presented for this conclusion, and the conditions required for the photoemission process to occur are demonstrated by several experiments. Important factors contributing to the efficiency of Cu&sngbnd;CdS photovoltaic cells of this type are: (a) the optical properties of copper, (b) the rectifying contact between the metal and CdS, (c) the good conductivity and high optical transparency which can be achieved in CdS crystals, and (d) the favorable relation between the work function of copper and the electron affinity of CdS.

ISSN:0021-8979    

DOI:10.1063/1.1735786

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

It has been established that when silicon is heated above 1300°K in a borosilicate glass vacuum system from 1011to 1015acceptors per cm2are normally added to the silicon surface, even though the glass walls remain at room temperature. The acceptor diffuses into the surface upon heating forming aplayer several microns deep.There is strong evidence that the acceptor is boron from the borosilicate glass envelope. The transfer to the silicon is believed to occur through volatilization of boron oxides by water vapor.

ISSN:0021-8979    

DOI:10.1063/1.1735787

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

Paramagnetic susceptibilities of Fe and Fe‐Si alloys (5.75, 6.82, 9.45, 12.65, 14.70, 18.11, 20.85, and 24.38 at. % Si) have been measured up to 1200°C. At high temperatures the paramagnetic susceptibilities of bcc Fe‐Si alloys obey the Curie‐Weiss law, possibly indicating that the contribution due tos‐dexchange interactions is small in comparison with the temperature dependent paramagnetism. The effective Bohr‐magneton number of Fe from the high‐temperature region is independent of Si content up to about 14 at. % Si. At higher Si concentrations, gradual decrease in the effective Bohr‐magneton number occurs. According to the paramagnetic susceptibility measurements, the &agr;‐&ggr; transition in iron takes place at 910±3°C. Assuming that the critical temperatures for chemical ordering as given by Glaser and Ivanick are correct, our measurements indicate that the paramagnetic susceptibility, within the experimental error, is not influenced by the destruction of the superlattice above 13 at. % of Si.

ISSN:0021-8979    

DOI:10.1063/1.1735788

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

A new method of producing thin layers of indium antimonide is described. This consists of suddenly squashing a drop of molten indium antimonide between two optical flats and allowing it to cool.Large area, self‐supporting specimens of 10‐&mgr; thickness have been prepared in this way and their properties examined. Although these layers are polycrystalline, their electrical and optical properties are in good agreement with the single‐crystal materials from which they were obtained.

ISSN:0021-8979    

DOI:10.1063/1.1735789

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

Germanium layers have been formed on single‐crystal Ge substrates by the thermal decomposition of GeI2. The single‐crystal nature of the layers has been established by x‐ray and electron diffraction examination and by electrical measurements. The deposition process is described briefly. The crystal growth rate varies with crystal direction, and under certain conditions Ge whiskers appear. The layers as deposited are generallyntype; &rgr; ranges from 1 to 5 ohm‐cm and &mgr;Hfrom 1200 to 2700 cm2/v‐sec at room temperature. A donor level is found approximately 0.2 ev below the conduction band, with a concentration of active centers of about 1016/cm3. Heat treatment at 550°C gradually converts the layers toptype, for which &rgr; is 10 to 40 ohm‐cm and &mgr;H1500 to 2400 cm2/v‐sec at room temperature; an acceptor level is found at about 0.05 ev above the valence band, with a density of active centers of 1014to 1015/cm3. The layers can be doped intentionally to produce either conductivity type, permitting fabrication of junction devices. Although iodine and other impurity atoms are considered, it is concluded that interstitial Ge atoms and lattice vacancies, occurring in unequal numbers at the time of deposition, are the most likely source of the donor and acceptor levels, respectively, and of the observed heat treatment properties.

ISSN:0021-8979    

DOI:10.1063/1.1735790

出版商:AIP    

年代:1960

数据来源: AIP