摘要:

Annealing behavior of neutron‐produced defects in silicon was studied by measuring the phase angle &Vthgr; of the small‐signal transconductance of the junction field‐effect transistors (JFET’s). Three deep levels (N‐1, N‐2, and N‐3 levels) inn‐type silicon and two deep levels (P‐1 and P‐2 levels) inp‐type silicon, introduced by irradiation, annealed gradually. Their energy levels and capture cross sections have been already reported by us. Three deep levels (P‐3, P‐4, and P‐5 levels) were observed in annealedp‐type silicon in the temperature range 150–300 °C. For these defects, &Vthgr; was measured as a function of frequency to obtain the time constant. From the temperature dependence of the time constant, assuming that capture cross sections are independent of temperature, the energy levels of P‐3, P‐4, and P‐5 were estimated to beEv+0.21,Ev+0.40, andEv+0.30 eV, respectively. The calculated hole capture cross sections of these levels were 2.2×10−15, 8.7×10−14, and 1.2×10−14cm2, respectively. Comparison with other published data was made. It was found that N‐3 and P‐2 levels corresponded to the divacancy. Furthermore, it seemed that P‐3, P‐4, and P‐5 levels corresponded to the high‐order vacancy defects.

ISSN:0021-8979    

DOI:10.1063/1.324319

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The effects of electron irradiation on the Bordoni peak and on dislocation drag were investigated by means of internal friction and modulus defect measurements over the temperature range 4.2–350 °K. These measurements were made during dynamic irradiations as a function of time and prior to and following irradiation as a function of temperature. It was found that (1) with a moderate dose irradiation the Bordoni peak height decreased 100‐fold and (2) that a well‐defined defect‐dragging peak evolved during electron irradiation at 4.2 °K. This peak is similar but somewhat subdued in height in comparison to the peak previously observed at room temperature by the authors. The reduction in the Bordoni peak height following irradiation is examined in terms of several existing kink models, as well as in terms of stress‐assisted defect drag.

ISSN:0021-8979    

DOI:10.1063/1.324320

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A method is presented for obtaining the ultimate strength of solids in the absence of defect motion. The procedure which involves finite elasticity theory and measured higher‐order elastic coefficients is utilized to compute the ultimate tensile and compressive yield stress of germanium and silicon crystals loaded in the [100] direction. These results are used as the basis for estimating the ultimate compressive strength of diamond.

ISSN:0021-8979    

DOI:10.1063/1.324321

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The release of solids from a state of shock compression at a free surface is examined. For isentropic release, the postshock specific volumeV′0is shown to be constrained byV′0? (Ufs−Up)2/P1+V1, where (P1,V1) is the pressure‐volume Hugoniot state of shock compression andUfsandUpare the free‐surface and shock particle velocities, respectively. When a sudden phase change occurs during the release process, this lower bound is increased, subject to simplifying assumptions about the phase transition.

ISSN:0021-8979    

DOI:10.1063/1.324323

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Values of the nonlinearity constantDwhich determines the coupling of acoustic phonons with the thermal phonons have been evaluated for the semiconducting material germanium in the temperature range 297–78.9 °K using the experimental data of second‐ and third‐order elastic constants of this material. The temperature‐dependent behavior of this constant has thus been tested for the first time on a theoretical basis through ultrasonic attenuation evaluated for high‐frequency compressional waves, propagating along the ⟨100⟩ direction in single‐crystal germanium. The results obtained are found to be in excellent agreement with the experimental values observed previously.

ISSN:0021-8979    

DOI:10.1063/1.324324

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Pressure‐volume relationships for the bcc transition metals in the groups VB (V, Nb, and Ta) and VIB (Cr, Mo, and W) were determined under hydrostatic pressure to 100 kbar at room temperature by means of x‐ray diffraction, employing diamond‐anvil pressure cell and the ruby (R1line) fluorescence calibration technique. Using the measured ultrasonicK′0values, whereK0is the bulk modulus at ambient pressure, for five metals and the deduced shock‐waveK′0value for Cr, the values ofK0for V, Nb, Ta, Mo, W, and Cr are calculated to be 1.54, 1.71, 1.94, 2.67, 3.07, and 1.93 Mbar, respectively, by least‐squares fit of the experimentalP‐Vdata to the Birch‐Murnaghan equation. TheK0values thus determined are in good agreement with the ultrasonic and shock‐wave values for V, Nb, Ta, Mo, and W. For Cr, theK0value (1.93 Mbar) is in agreement with the shock‐wave value (1.92 Mbar) but not with the ultrasonic value (1.65 Mbar). This discrepancy can be explained in view of the paramagnetic→antiferromagnetic transition in Cr in the temperature proximity of the ultrasonic measurements (Neel temperatureTN∼311 °K at 1 bar) and by the negative pressure dependence ofTN.

ISSN:0021-8979    

DOI:10.1063/1.324325

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The thermal expansion of glassy metals of general composition (FexNi1−x)0.75P0.16B0.06Al0.03has been determined. The thermal expansion &agr; was found to vary smoothly between 1.07×10−5deg−1forx=0.2 to 0.75×10−5deg−1forx=1. The glassy metals considered here are only available in thin‐ribbon form and, therefore, cannot be measured by techniques that require compressive loading of the sample. The method used here employs a linear‐variable‐differential transformer to monitor the elongation of a ribbon that is under slight tension.

ISSN:0021-8979    

DOI:10.1063/1.324326

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The quasiharmonic approximation is used to calculate the Helmholtz free energyF. The interionic forces are represented by a deformation‐dipole model, which is parameterized self‐consistently. We give parameterized expressions forFthat can be used to predict the temperature and volume dependence of the thermodynamic properties of CsCl, CsBr, and CsI. These expressions forFare tested by comparing our predicted values for the heat capacityCPand the thermal expansion &agr; with experimental atmospheric‐pressure values. Good agreement is obtained. Predicted values forCV, &agr;,BT, the compression −&Dgr;V/V0, and the Gru¨neisen &ggr; at elevated pressures are given, as are zero‐pressure values for the logarithmic derivativeqT= (∂ln&ggr;/∂lnV)Tand the Anderson‐Gru¨neisen parameters &dgr;Sand &dgr;T.

ISSN:0021-8979    

DOI:10.1063/1.324327

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A theoretical treatment is given of ’’partial’’ sinks, i.e., those in which the amount of a diffusing species removed through a surface is proportional to its concentration there. The effect of the existence of a partial sink on the concentration profiles and on the amount of material which accumulates on the surface is treated. Diffusion coefficients calculated from measured data will be in error if a perfect sink is assumed when a partial sink actually exists. The magnitude of this error is considered.

ISSN:0021-8979    

DOI:10.1063/1.324335

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The chemical diffusion coefficients and the solubility limits of iron in copper were determined in the temperature range 650–1050 °C by electron probe microanalysis. Specimens were 99.999&percent; copper single crystals. The diffusion is best described by two regression lines:DFe‐Cu=0.504 exp(−49740/RT) cm2/s for the temperature interval 1050–800 °C andDFe‐Cu=0.091 exp(−46140/RT) cm2/s for the temperature interval 800–650 °C. The solubility of iron in copper is given to logC=2.951−3357(1/T °K) wt&percent; in the temperature range 1050–650 °C.

ISSN:0021-8979    

DOI:10.1063/1.324336

出版商:AIP    

年代:1978

数据来源: AIP