摘要:

AbstractThe overlapping two‐band model for the transverse magnetoresistance, originally proposed by Sondheimer and Wilson (1947), and the magnetoresistance in a mixed nondegenerate semiconductor with contributions from both the conduction and the valence bands is reconsidered. It is shown that the classical answers for both cases are readily obtained by using the tensor‐relaxation time formalism. introduced by Van Vliet and Marshak (1976). More detailed extensions are also gi

ISSN:0370-1972    

DOI:10.1002/pssb.2221870116

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractIn connection with the charge‐separation model of photoinduced second‐harmonic generation in optical fibres based on the coherent photogalvanic effect the tensorial properties of the coherent photocurrent in glass are studied using a phenomenological approach with the randomness of the glass taken into account. Since the most general expression is used for the coherent photocurrent, this approach is valid for any microscopic model of the coherent photogalvanic effect. The dependence of the photocurrent on the polarization of fundamental and second‐harmonic waves is obtained. Directional photoionization of localized states is studied explicitly in connection with experiments with circularly polarized waves performed rec

ISSN:0370-1972    

DOI:10.1002/pssb.2221870117

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe general theory of a third‐order generalized photoconductivity in glass is developed using a density matrix approach in the generalized master equation approximation. The theory is applied to third‐order photogalvanic effect in glass in connection with photoinduced second‐harmonic generation in s

ISSN:0370-1972    

DOI:10.1002/pssb.2221870118

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe observation and detailed investigation of the highly reproducible transition with onset at 130 K are reported in samples of Bi oxides (both 2212 and 2223 systems) doped with iron phthalocyanine, involving effects of temperature, magnetic field, and chemical composition on dc magnetization and microwave absorption spectra of the samples. The experimental magnetic data are suggestive of a superconducting nature of the transition; however, no reliable electrical resistivity drop is observed at 130 K to confirm the occurrence of superconductivity.

ISSN:0370-1972    

DOI:10.1002/pssb.2221870119

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe analytical expressions for dispersion relations, cross‐over effect conditions, effective penetration depth, surface impedance, and inflection linewidth for FMR in bulk metals in normal configuration are derived including electrical conductivity and the Landau‐Lifshits damping parameter (for the case of zero surface pinning). The possibility of excitation of Larmor and anti‐Larmor Kittel and surface modes in materials with negative surface anisotropy is investi

ISSN:0370-1972    

DOI:10.1002/pssb.2221870120

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe method of solid state reactions is used to synthesize the samples of Eu0,5RE0,5Fe0,5Mn0,5O3(RE = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Y). XRD and57Fe Mössbauer spectra are measured. It is found that the volume of the unit cell of the samples decreases with increasing atomic number of RE. The Fe ions are in the Fe3+high spin state, and the relationship between the quadrupole splittings and the lattice distortion parameterDof the samples is linear

ISSN:0370-1972    

DOI:10.1002/pssb.2221870121

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe frequency dependence of the real and imaginary parts of the complex dielectric constant ϵ(ω) in compounds XMnY (X = Ni, Pd, Pt, Cu; Y = Sb, Sn) having Clbstructure are investigated in the spectral range ħω = 0.05 to 8 eV. The values of conduction electron plasma and relaxation frequencies ωpand γ, respectively, are determined. The evolution of interband conduction and electron energy‐loss function ‐Im (ε−1) for varying compositions is studied. In all the compounds, apart from the main absorption band located in the spectral range 1 to 7 eV, a low‐energy (ħω = 0.3 to 0.7 eV) interband absorption is revealed. An estimation is made of the energy gap at point Γ of the Brillouin zone in the minority‐spin subbands (↓) for NiMn

ISSN:0370-1972    

DOI:10.1002/pssb.2221870122

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractLight oscillations due to internal switching delay in optically bistable CdS platelets are reported using a geometry with two exciting beams. It is shown that in the case when one of the exciting beams has the form of a long thin light strip, an internal delay occurs due to the final propagation speed of the bistable switching front along it (switching wave) which enables one to obtain oscillations using electrooptical feedback without external delay. If an external delay is applied to one of the beams, while the second one appears as a single light pulse peculiarities of the oscillations caused by the interaction of both delay signals are obtained, which are not observed if only one light beam is used.

ISSN:0370-1972    

DOI:10.1002/pssb.2221870123

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractSbSI:V, SbSeI:V, BiSI:V, and BiSeI:V single crystals are grown by the vertical Bridgman technique using ingots synthesized from mixtures of the elements (purity 99.9999%). The grown single crystals have an orthorhombic structure and an indirect energy band structure. The temperature dependence of the optical energy gap is well fitted by the Varshni equation. Impurity optical absorption peaks due to the doped vanadium appear and are assigned to the electron transitions between the energy levels of the V2+ion located at Tdsites of the host lattice.

ISSN:0370-1972    

DOI:10.1002/pssb.2221870124

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221870101

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY