摘要:

AbstractThe influence of uniaxial stress in 〈111〉 direction on the free carrier contribution to the optical constants of multivalley semiconductors is considered according to the electron transfer model. Calculations are made of the resulting change in absorption and shift of the wavelength for minimum reflection. It is shown that these effects may be large and experimental observation of them provides a method of determining the effective mass and relaxation time parameters and their anisotropies. The possibility of constructing infrared modulators based on these phenomena is also exami

ISSN:0370-1972    

DOI:10.1002/pssb.2220430139

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe stacking faults in Shockley type loops, observed in iridium field‐ion images, have been analyzed for the type of fault, using a method developed in a previous paper [1]. In all cases where the identification was possible, the faults were found to be extrinsic. This result is discussed in the light of the origin of the defects, and related to the large negative hydrostatic pressures that occur in field‐ion specim

ISSN:0370-1972    

DOI:10.1002/pssb.2220430140

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe use of stress relaxation methods to establish the parameters describing dislocation mobility have been critically examined. It is shown that the values of internal stress established from the condition of zero relaxation rate are temperature independent and equivalent to the athermal component of the flow stress. The various methods of establishing the internal stress are in accord providing cogniscence is taken of the experimental limitations of the technique.

ISSN:0370-1972    

DOI:10.1002/pssb.2220430141

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractMössbauer effect measurements for a series of iron compounds of the type CaxFe3−xO4(0 ≦x≦ 0.55), known as calcium‐magnetites, are performed at room temperature and liquid nitrogen temperature. A single calcium‐magnetite phase giving Mössbauer spectra with magnetite‐like Zeeman splitting was observed up tox≈ 0.28. For higher Ca concentrations a second phase, represented by the additional quadrupole doublet, was detected. This new phase may be identified as

ISSN:0370-1972    

DOI:10.1002/pssb.2220430142

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractAn expression for the electronic spin polarizationp(r) due to s‐d exchange interaction between the conduction electrons and the localized impurity of spin 1/2 in a dilute magnetic alloy is obtained by using the one particle Green function approach. For large distancesp(r) is found to exhibit exponentially damped behavior. This feature ofp(r) was also predicted earlier by Bose, Tanaka, and Halow by using the method of cluster variation of the co‐operative phenom

ISSN:0370-1972    

DOI:10.1002/pssb.2220430143

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe thermodynamic Green function of a weak anharmonic crystal, obtained through the equation of motion method, has been used to derive an explicit expression for the interaction energy. The Helmholtz free energy (F) has been obtained by integrating this interaction energy over a formal coupling parameter. Under certain conditions the expression forFhas been shown to be identical with that obtained from perturbation theory and diagrammatic methods.

ISSN:0370-1972    

DOI:10.1002/pssb.2220430144

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractPartial thermal annealing of nominally pure calcium tungstate, after gamma irradiation at 78 °K, provided evidence for identifying three major 4900 Å thermoluminescence peaks at 0.36, 0.55, and 0.72 eV with three groups of electron spin resonance lines of paramagnetic tungsten atg001= 2.009 and 1.843 and niobium atg001= 2.021, respectively. The impurity center identified with the paramagnetic Nb+4ion is assigned to a tungsten site and a NbO 4−4complex. Arguments are presented for the assignment of two lattice defect models, a WO 4−3complex with nearby WO3and NbO 4−3complexes, and a WO 3−1complex with a nearby calcium deficiency, to the paramagnetic (W+5)Aand (W+5)Bi

ISSN:0370-1972    

DOI:10.1002/pssb.2220430145

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe paper develops and supports in some detail the hypothesis that the well‐known “three‐stages work‐hardening” curve of b.c.c. metals is closely analogous, beyond its inflexion point, to stage‐III work‐hardening of f.c.c. metal single crystals. The basic reason for this correspondence is that in both cases screw dislocations may cross‐slip easily. A qualitative picture for stage‐III hardening in f.c.c. metals and for the work‐hardening of b.c.c. metals based on the internal stresses originating from dislocation sheets parallel to the primary glide plane (or the glide plane of maximum shear

ISSN:0370-1972    

DOI:10.1002/pssb.2220430146

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2220430101

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY