摘要:

AbstractThe soltion solutions to the continuum equations of motion of the trans‐(CH)xmodel in the limit of slowly moving solitons are obtained. The effects due to the soliton motion are considered. The main physical characteristics of moving solitons (the energy of creation, mass, charge, width, electrical moments) are calculated. In the case of the kink excitation the effects of motion are reduced by the small parameter ϵ ≈ 0.07, whereas for the polaron excitation the correction terms proportional to the polaron velocity are consider

ISSN:0370-1972    

DOI:10.1002/pssb.2221370216

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractAn effective medium approach (CPA) for calculating the static wave‐number‐dependent effective dielectric function of strongly heterogeneous composites with randomly oriented anisotropic components is presented, where the composite is supposed to consist of a random arrangement of homogeneous regions (grains) with known material properties. Final formulae governing the effective dielectric function at arbitrary wave numbers are given for spherical and cylindrical grain shapes. In the long‐wavelength limit the general case of ellipsoidal shape is considered and a marked dependence of the effective permittivity on the eccentricity is obtained for moderate and large aniso

ISSN:0370-1972    

DOI:10.1002/pssb.2221370217

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe absorption of SnSe single crystal is studied near the absorption edge at 95 and 295 K in polarized light for ϵ |aand ϵ |b, whereaandbare crystallographic axes within the cleavage plane. Two indirect transitions (0.907 and 1.01 eV at 295 K) are identified for both orientations and a first direct transition for ϵ |bwithE0d= 1.051 eV and for ϵ |awithE1d= 1.236 eV as well, all at 295 K. The temperature coefficients of all transitions are determined also within the range of 95 to 295 K. Also is suggested the interpretation of these results considering the band structure of SnSe given in the literat

ISSN:0370-1972    

DOI:10.1002/pssb.2221370218

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractElectronic properties of the titanium clusters Ti4(Td) and Ti6(Oh) are calculated by means of the semiempirical quantum chemical CNDO method. The parameters are derived by adjusting the cluster electronic properties to the corresponding bulk data. Comparing the titanium cluster results with those of small nickel clusters calculated using Blyholder parameters, the same trends are observed as in comparing the bulk properties of both metals. An application of the titanium parameters to the calculation of the intermetallic compound Ni3Ti gives a further confirmation of their compatibility with the nickel parameters. Using the derived parameters in TiO2cluster calculations leads to a satisfactory description of the electronic properties of this material.

ISSN:0370-1972    

DOI:10.1002/pssb.2221370219

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractMagnetic circular dichroism (MCD) measurements are carried out on Si monocrystals in longitudinal magnetic fields up to 5.3 T. Near the indirect excitonic absorption many oscillations occur in the MCD spectra. In comparison with wavelength‐modulated absorption measurements it is shown that the MCD oscillations are due to strongly broadened steps in the absorption edge. The characteristic energies of the absorption steps behave like that of Landau levels with a phenomenological effective mass ofm* = 0.38 ± 0.04 forB| [001], obtained also by cyclotron resonance experiments. The energies of the Landau‐like steps converge withB→ 0 to energies near the series limit of the exciton. It seems to be the first time that Landau levels in the magnetoabsorption in Si are me

ISSN:0370-1972    

DOI:10.1002/pssb.2221370220

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractCalculations of the Compton profiles for the transition metals Ta and W are performed, using electron wave functions obtained from self‐consistent augmented plane wave (APW) band structure calculations within the local density formalism of Hedin‐Lundqvist. Relativistic effects are included except for the spin‐orbit interaction. The observed structures of the Compton profiles in these metals are understood in terms of the topology of their Fermi sur

ISSN:0370-1972    

DOI:10.1002/pssb.2221370221

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe influence of the intersubband transitions on p‐polarized infrared spectrum of size‐quantized Bi films with normal along trigonal axes is investigated. The optical conductivity is evaluated using the two‐band model. Results indicate that contrary to Cottey's theory the absorption lines connected with intersubband transitions are very

ISSN:0370-1972    

DOI:10.1002/pssb.2221370222

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe oscillator strength for electric‐dipole transitions and the photoionization cross‐section of impurities in GaAs/Ga1–xAlxAs heterojunctions are calcu

ISSN:0370-1972    

DOI:10.1002/pssb.2221370223

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe EPR spectrum of the Cu2+ion in octahedral environment is calculated with the account of the Jahn‐Teller effect within the cluster model. The study of the frequency dependence of the EPR spectrum is used as a basis for the estimation of parameters of the Hamiltonian describing the behaviour of the system. The appearance of an additional isotropic line and drop of intensities of the resonance lines of the low temperature spectrum with the temperature increase are explained on the basis of the population of a great number of excited states and their propertie

ISSN:0370-1972    

DOI:10.1002/pssb.2221370224

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe local density of electronic states is calculated on the (111) surface of silicon with disordered adsorption of atomary hydrogen with an arbitrary degree of coverage. Computations are made by the recursion method and the method of generalized Bethe lattices. The dependence of the electronic density of states on the degree of coverage of the surface by hydrogen is investigated. The results obtained by the recursion method and the generalized Bethe lattice method are compared with those obtained by other methods and by the experiment and a good overall agreement is found. The contribution of hydrogen and silicon atomic states into the electronic structure of the Si(111) surface is analyzed.

ISSN:0370-1972    

DOI:10.1002/pssb.2221370225

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY