摘要:

Ternary alloys containing nickel, palladium, and phosphorus have been obtained in an amorphous form by rapid quenching from the liquid state. These alloys contain from 13–73 at.% Ni, 15–20 at.% P with Pd adding up to 100%. The electrical resistivity of these alloys has been measured from 4.2°K to about 850°K, which is close to their melting point. A Kondo effect, probably due to very small concentration of iron impurities, has been observed in all the alloys below 15°K. Between 15° and about 40°K, the resistivity increases with temperature likeT2and then linearly up to about 550°K. The very small temperature coefficient of resistivity (around 10−4/°C) is attributed to the high degree of structural disorder in the amorphous alloys. Above about 570°K, the amorphous alloys transform progressively into crystalline phases, The variation of electrical resistivity with temperature in specimens heated at rates of about 1.5°C/min was correlated with structural changes observed by x‐ray diffraction.

ISSN:0021-8979    

DOI:10.1063/1.1658703

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Total ionized impurity densities (ND+NA) from 7×1013to 3×1017cm−3are determined for epitaxial samples ofn‐type GaAs by analyzing mobility and carrier concentration data as a function of temperature with the Brooks‐Herring formula for ionized impurity scattering. This procedure results in the determination of a temperature range within which the effects of other scattering mechanisms are minimal and gives values ofNDandNAwhich are in good agreement with impurity densities obtained from analyses of the temperature variation of the Hall constant. These results are then used to determine empirical curves relating the impurity density to the 77°K Hall mobility. With these data a good estimate of the total ionized impurity concentration in a sample can be determined from Hall constant and resistivity measurements at 77°K.

ISSN:0021-8979    

DOI:10.1063/1.1658704

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

The general problem of double injection into a perfect insulator, free of traps and of thermal free carriers, does not yield to a complete, analytical description. A complete solution is presented for the limiting cases of very large and very small &sgr;R, where &sgr;Ris the electron‐hole recombination cross section. The first situation corresponds to a pair of back‐to‐back, one‐carrier, space‐charge‐limited currents, the second to an injected plasma. TheI‐Vcharacteristics obtained in these two limits agree precisely with the earlier general analytical result of Parmenter and Ruppel. For intermediate values of &sgr;Rthe Regional Approximation method is used to obtain an approximate solution. The field and density distributions, obtained for large, intermediate, and small values of &sgr;R, are the first available for this problem. The constant‐lifetime and bimolecular‐recombination injected plasmas are compared and found to have remarkably similar distributions.

ISSN:0021-8979    

DOI:10.1063/1.1658705

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

The interaction of point defects with dislocation ribbons was studied experimentally by observation of vacancy clusters in deformed pure silver by means of electron microscopy. The results were in good agreement with theoretical predictions: The energy of the interaction was attractive, increased as the dislocation became more edge‐like in character, and decreased as the width of the dislocation ribbon increased.

ISSN:0021-8979    

DOI:10.1063/1.1658706

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

By thermal grooving, the energy of an &agr;‐iron deformation twin boundary was determined and compared with the energy of an &agr;‐iron annealing twin boundary. The stacking fault energy was approximated and compared with that of other bcc iron alloys.

ISSN:0021-8979    

DOI:10.1063/1.1658707

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Several arrangements are suggested to explain deviations from stoichiometry in LiNbO3in a recent report by Lerner, Legras, and Dumas. These arrangements are considered to be unlikely, and an alternative mechanism in terms of partial stacking faults is proposed for LiNbO3and LiTaO3. A microscopic statistical theory of ferroelectricity, which is outlined, can predict the variation of the Curie temperature with changes in the bonding forces and atomic masses. Using this approach, the stacking‐fault model is consistent with the observed variation of Curie temperature with composition.

ISSN:0021-8979    

DOI:10.1063/1.1658708

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Metal‐insulator‐metal systems are discussed in which the insulator is highly doped and in which Schottky barriers exist at the metal‐insulator interface. An equivalent circuit for the system is proposed and the ac electrical characteristics derived. It is shown that the capacitance isextremelytemperature and frequency dependent. At high frequenciesorlow temperatures the capacitance is thickness dependent and equal to the geometric capacitance. At low frequenciesandhigh temperatures it is thickness independent and equal to the Schottky barrier capacitance, which is determined by the doping density. Several methods of determining the activation energy of the donor centers from experimental capacitance versus frequency and temperature curves are suggested. The parallel equivalent conductance is also shown to be extremely frequency and temperature sensitive. It is found to have a pronounced maximum in both cases, which increases in magnitude and occurs at higher temperatures the thicker the insulator.

ISSN:0021-8979    

DOI:10.1063/1.1658709

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Thin film capacitors of MoO3are found to be extremely temperature and frequency dependent. Changes in capacitance are reported as high as 60:1 over a temperature range of 100°C (at constant frequency) and over a two‐decade frequency range (at constant temperature). At lower temperatures and higher frequencies the capacitance corresponds to the geometric capacitance, but at higher temperatures and lower frequencies the capacitance isindependentof the film thickness. Conductance and quality factor of the films are also observed to be extremely frequency and temperature sensitive. The results are explained in terms of Schottky barriers existing at the metal‐insulator interfaces, which arise due to the autodoping of the insulator, occurring during deposition of the films, by excess molybdenum. Excellent agreement is found to exist between the experimental data and the theory developed in the previous paper, and this correlation permits determination of the doping density (≃1018cm−3), the donor depth (≃0.27 eV), and the width of the Schottky barriers (≃160 Å), among other properties of the films.

ISSN:0021-8979    

DOI:10.1063/1.1658710

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A model is given for the resistive‐conductive transition in an amorphous or crystalline bistable resistance switch. The model is based on the observation that the current path in the switch is filamentary. The hypothesis is that the switching current heats the filament, and the resistive‐conductive transition occurs only after the filament has achieved a critical temperatureTc. The predictions of the model are in excellent agreement with experimental observations of the resistive‐conductive transition in single‐crystalline Cu2O.

ISSN:0021-8979    

DOI:10.1063/1.1658711

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Radiation fields in moving uniaxial media have been quantized without introducing auxiliary potential functions. Hamiltonian and momentum operators are diagonalized in momentum space and written in terms of annihilation and creation operators of the photon state. It is found that two types of photons corresponding to classical ordinary and extraordinary waves will exist, and they are called ordinary photons and extraordinary photons. Physical interpretations of the various results are discussed.

ISSN:0021-8979    

DOI:10.1063/1.1658712

出版商:AIP    

年代:1970

数据来源: AIP