bluuebunny/crossref_metadata_2025_split huggingface dataset:
Faraday Rotation and Magnetic Dichroism in RbNi(Co)F3
Authors: Pisarev R. V. , Siny I. G. , Nesterova N. N. , Smolensky G. A. , Syrnikov P. P. 
Published: July 2007

AbstractThe optical and magneto‐optical properties of hexagonal ferrimagnetic RbNi(Co)F3 (Co2+ content ≈ 23%, Tc = 109°K) have been studied in the region 0.28 to 12 μm. It is confirmed that this crystal may be regarded as an “easy axis” ferrimagnet. Absorption lines have been interpreted as arising from electronic transitions between crystal field levels of 3 d‐configuration of Ni2+ and Co2+. Below Tc a strong anomalous dispersion of Faraday rotation and magnetic circular dichroism was found in the absorption line regions. The origin of these effects is assumed to be associated with exchange splitting of electronic states of Ni2+ and Co2+ below Tc and with unequivalency of 4f and 2a magnetic sublattices in the hexagonal structure.
Lifetimes of Current Carriers in InP
Authors: Kovalevskaya G. G. , Slobodchikov S. V. 
Published: July 2007

AbstractThe lifetimes of electrons and holes in p‐ and n‐type InP are measured in the temperature range 78 to 300°K. Possible mechanisms for the capture and recombination with participation of several trapping centres: E = 0.17 eV, E = 0.04 to 0.06 eV, E = 0.10 eV, are suggested. The considerable effect of trapping at low temperatures is noted. It is found that for low‐resistivity p‐type samples the recombination centres d2 and the trapping centres f1, and for high‐resistivity samples the centres d2 and f2 play the dominant role. As result of effective trapping in n‐type as well as in p‐type InP the lifetimes of electrons and holes differ much at low temperatures.
Polariton Dispersion in Biaxial and Uniaxial Crystals
Authors: Merten L. 
Published: July 2007

AbstractComplete dispersion relations of polaritons are given for biaxial and uniaxial crystals. In the limiting cases k → 0 and k → ∞ (k wave vector) very general conclusions can be drawn concerning their frequencies and directions of polarization. For uniaxial crystals the polaritons are subdivided in ordinary and extraordinary ones with orientation independent or orientation dependent frequencies, respectively. The ordinary polaritons are of transverse type whereas extraordinary are of mixed transverse‐longitudinal type for a general orientation.
Effect of Neutron Irradiation on the Martensitic Transformation in β1‐Copper‐Zinc
Authors: Hummel R. E. , Koger J. W. 
Published: July 2007

AbstractResistivity measurements were used to determine the characteristic properties of the martensitic transformation in β1‐brass (39.4 wt% Zn) before and after neutron irradiation. The doses (Φ t) varied between 5 × 1016 and 5 × 1018 neutrons/cm2 (E > 1 MeV). Neutron irradiation decreased the martensitic‐start temperature (Ms) up to 8 °C and increased the maximum rate of trasformation. Ms was further decreased when β1‐brass was annealed at 150 °C after irradiation. A small decrease in Ms was observed when unirradiated, quenched β1‐brass was annealed at 150 °C. Possible mechanisms which give rise to the inhibition of the martensitic transformation, such as dislocation pinning, are discussed.
Atomistische Berechnung der Core‐Struktur, Core‐Energie und Peierls‐Spannung einer Stufenversetzung in NaCl
Authors: Granzer F. , Wagner G. , Eisenblätter J. 
Published: July 2007

AbstractDer Einfluß verschiedener elastischer Randbedingungen und Potentialansätze auf 1. das Verschiebungsfeld im Core‐Gebiet, 2. den Core‐Radius und die Core‐Energie, 3. die Peierls‐Spannung einer geraden (110), 1/2 [110]‐Stufenversetzung in NaCl wurde mit Hilfe eines Variationsverfahrens systematisch untersucht.
Electron‐Optic Investigation of the Magnetic Stray Field above Bloch Walls in Cylindric Nickel Crystals
Authors: Schwink Ch. , Schärpf O. 
Published: July 2007

AbstractAn electrostatic electron microscope of high magnification is developed for measuring low magnetic fields of small spatial extension. The method is applied to the investigation of the stray fields above the “convex” 71° Bloch walls of cylindric 〈110〉 Ni crystals causing the well‐known intense colloid lines. We find that these fields have dipole character and are closely related to the domain structure. The distance between the maxima of the both magnetic poles of the dipole stripe lying at the position of each convex Bloch wall varies from 4 to 10 μm. The normal field above the maxima amounts to about 25 Oe at the crystal surface. Generally, it is supposed that colloid patterns ‐ with the exception of very weak lines ‐ are due to dipole fields of the sort described.
Mechanical Interactions of Point Defects
Authors: Siems R. 
Published: July 2007

AbstractThe interaction of point defects, which are described by force multipoles, is treated using elasticity theory. Explicit expressions for the interaction energy are derived for elastically isotropic materials. For defects with cubic symmetry in f.c.c. metals, the lattice theory values derived for a special isotropic model (v = ∞) by Hardy and Bullough are 25% higher than the elastic theory values, both showing, however, the same orientation dependence and the same decrease with r−5. By finding not only the first (elastic) but also the second term of an asymptotic expansion of the lattice Green's function, the 25% difference is shown to be a true lattice theory effect.
On the Dynamical Behaviour of Excitons in CdS Single Crystals. I. Correlation between Intrinsic Excitonic Absorption and Emission
Authors: Voigt J. , Spiegelberg F. 
Published: July 2007

AbstractThe excitonic absorption and emission are investigated on the same, extremely thin (d ≈ 3 × 10−5 cm) CdS single crystals in the range 77°K to room temperature. It is found that the zero‐phonon emission line is strongly influenced by reabsorption. After a reabsorption correction of the emission data the conclusions from the absorption and emission investigations agree with respect to the exciton‐phonon interaction. There is a contribution to the halfwidths and energetic positions of the exciton lines which is proportional to a Bose factor of LO phonons with ħω1 = 38 meV. No evidence is found for polariton effects from the reabsorption correction of the emission data. It is concluded, from the temperature dependence of the total emission intensity, that a quasi‐equilibrium exists between excitons and electron‐hole pairs. The exciton ionization energy is determined to be 31.5 meV. The dependence of the total emission intensity from the excitation intensity shows the occurrence of non‐radiative recombination processes. Band shapes and intensity rations of the one‐and two‐phonon satellites in the emission are also investigated and discussed.
Mössbauer Effect in Simple Cubic Lattice with Line Defect
Authors: Celý J. 
Published: July 2007

AbstractA theoretical study is made of the Mössbauer effect in simple cubic lattices with a line defect for both the atoms inside and outside the perturbed region. Numerical calculations are made of the changes in the Debye‐Waller factor for a special type of defect (with variation of the mass and force constants along a single atomic row in [001] direction) in the classical approximation together with quantum corrections. Two methods, the high‐temperature expansion and another one which is valid for arbitrary temperatures, are used. A possibility of using graphs for some estimations, especially for the dependence of the quantum correction on the distance of the absorbing atom from the line defect, is suggested.
Dechannelling Cylinder of Dislocations
Authors: Quéré Y. 
Published: July 2007

AbstractA particle channelled in a crystal may be dechannelled when passing near a dislocation. This effect is simulated by an opaque cylinder dechannelling any particle hitting it. This cylinder is coaxial to the dislocation and has a diameter

E is the energy of the particle (charge Z1 e), b the Burgers vector, d the interatomic distance along the considered channel in the crystal Z2, a the screening radius, and α a number equal to 12.5 and 4.5 for screw or edge dislocations, respectively.
On the Thermodynamics and Paramagnetic Properties of Dispersed Metals
Authors: Czerwonko J. 
Published: July 2007

AbstractThe statistical thermodynamics of the electron gas in dispersed metals are developed. The assumptions are as follows: the one‐particle levels have the random character described by one of three possible Dyson ensembles with the homogeneous average level spacing δ. This value is of the order of the Fermi energy divided by the total number of electrons with possible surface corrections. The thermodynamical functions are explicitely calculated in two limiting cases: for kT much greater than δ and for kT much smaller than δ. In such a way we obtain the extension of Kubo's and Gorkov‐Eliashberg's results. The applicability of the present theory to transition metals is also discussed.
Röntgenographische Untersuchung des Übergangs vom Bereich I zum Bereich II der Verfestigungskurve kubisch‐flächenzentrierter Kupfer‐Gallium‐Einkristalle
Authors: Gassenmeier P. , Wilkens M. 
Published: July 2007

AbstractMittelorientierte Kupfer‐Gallium‐Einkristalle mit 2,5 bzw. 5 At% Gallium wurden im Zugversuch bei 78°K verformt. Aus den verformten Einkristallen wurden parallel zu verschiedenen kristallographischen Ebenen Oberflächen herauspräpariert und mit einem Röntgenrückstrahlverfahren abgebildet. Es wird gefunden, daß mit Beginn des Übergangs Bereich I/Bereich II Versetzungsschichten parallel zur Hauptgleitebene verstärkt auftreten. Aus Richtung und Vorzeichen der in den Versetzungsschichten enthaltenen Drehachsen wird geschlossen, daß die zum Aufbau der Schichten erforderliche Sekundärgleitung jeweils in der von äußeren Schubspannung begünstigten Richtung erfolgt und damit wohl nicht durch Versetzungsaufstauungen im Primärgleitsystem induziert wird.
Use of the Perturbation Theory in the Calculation of Adiabatic Potential
Authors: Ledovskaya E. M. 
Published: July 2007

AbstractThe energy of an electronic state of a complex system, consisting of a number of interacting sub‐systems is considered by perturbation theory, the interaction of sub‐systems being taken as a perturbation. The energy of a system is calculated up to the second order and the wave function up to the first order. The application of perturbation theory is justified when in the expansions in terms of nonorthogonal functions of an overcomplete set the coefficients possess the minimum property.
The Effect of Impurities on the Thermoelectric Properties of Bi, Te, and Se at Phase Transitions
Authors: Dutchak Ya. I. , Klyus I. P. , Prokhorenko V. Ya. 
Published: July 2007

AbstractThe thermo e.m.f. of Zn, Ga, In, Sn, and Bi doped (1 and 1.5 wt%) Bi, Te, and Se is investigated over a large temperature range using solid as well as liquid samples (for Se the amorphous state is also included). The dopants Zn, Ga, In, and Sn strongly affect the thermo e.m.f. of solid but not of liquid Bi. Liquid Te and Se are found to show semiconductor properties determined strongly by impurities, especially for Se. The change in the sign of the thermo e.m.f. of liquid Se is explained by the existence of oxygen atoms acting as acceptors.
An Account of Configuration Interactions in Group‐Theoretical Classification of Electronic States in Crystals Composed of Complexes of Bound Impurity Ions
Authors: Vonsovskii S. V. , Men A. N. , Cherepanov V. I. , Karpenko B. V. , Farberov D. S. , Nikolaev A. P. , Mitrofanov V. I. , Chufarov G. I. 
Published: July 2007

AbstractA group‐theoretical classification of the states of paramagnetic impurity ions is made taking into account charge transfer. The cases of an impurity ion in a spinel crystal and the first order pair of equivalent Cr3+ ions in corundum are studied as examples. A group‐theoretical classification of the states of complexes of N impurity ions (N = 2 to 4) is given. KMg(Co)F3 is discussed as an example.
Effective Mass Approximation for Acceptor States in Silicon
Authors: Mendelson K. S. , Schultz D. R. 
Published: July 2007

AbstractThe effective mass equations for acceptors in silicon have been solved approximately for a large number of excited states. The variational approach used by Schechter was followed, but with more general trial functions that allow the treatment of a larger number of excited states. More recently measured valence band parameters were also used. Energies and wave functions were calculated for all of the lower excited states. Several energy levels were found between the levels treated by Schechter. The energy values obtained from the new valence band parameters do not agree as well with experiment as those obtained with the older parameters. However, the new distribution of levels does yield a better agreement between the theoretical and experimental symmetries of the excited state wave functions.
Properties of Exciton States in NaI. II. Excitonic Energy Transfer to Q and Tl Centers
Authors: Blume H. , Fontana M. P. , van Sciver W. J. 
Published: July 2007

AbstractAs reported in Part I, upon excitation in the region of the first excition absorption band the efficiency of the intrinsic luminescence of NaI decreases with decreasing temperature below 60 °K. This part of our article yields information about the fate of the excition generated at low temperatures: 1. Only a very small fraction of the excitons contribute to thermoluminescence. 2. The exciton state is not the excited state of an emission with a small Stokes shift ΔE ≧ 0.1 eV. 3. However, an excitonic energy transfer to Q and Tl centers takes place. The lifetime of the exciton state in a crystal doped with 1 ppm of each Q and Tl centers is τ < 5 ns at LHeT.
Phononenstruktur im Emissionsspektrum dotierter Naphthalinkristalle
Authors: Ostertag R. , Wolf H. C. 
Published: July 2007

AbstractIm Emissionsspektrum dotierter Naphthalinkristalle beobachtet man bei tiefen Temperaturen charakteristische breite Mehrphononenbanden als Begleiter der scharfen Null‐Phonon‐Linien, die zu elektronisch‐vibronsichen Übergängen in den Gastmolekülen gehören. Die Phononen‐Zustandsdichte des Wirtkristalls verwendet wurden.
Magnetic Susceptibility Measurements of Mixed Transition Metal Germanides
Authors: Airoldi G. , Asdente M. , Drosi M. 
Published: July 2007

AbstractMagnetic susceptibility measurements on (Fe1−xYx)1.67Ge with B82 structure, where Y is another 3d transition element, are performed in the range between room temperature and 1000°C. For all of them the magnetic susceptibility follows a Curie‐Weiss law at high temperature. The results are examined in comparison with the ones found transition metal alloys.
Ferromagnetic Behavior of Iron Alloys Containing Molybdenum, Manganese, and Tantalum
Authors: Arajs S. 
Published: July 2007

AbstractThe mass magnetization of iron‐rich binary iron solid solutions, containing molybdenum, manganese, and tantalum, have been studied as a function of the internal magnetic field at 298 °K. The mass spontaneous magnetizations have been determined from these data using the Belov‐Arrott‐Kouvel method. Our values of the spontaneous magnetization as a function of molybdenum or manganese concentration are in fair agreement with previous investigations of the saturation magnetization by Aldered and Sadron, respectively. The spontaneous magnetizations for iron‐tantalum alloys have been measured for the first time. These investigations indicate that, from the viewpoint of the bulk magnetization, molybdenum, manganese, and tantalum very approximately produce a simple dilution effect.
Electrical Conductance of Rubidium Nitrate
Authors: Salhotra P. P. , Subbarao E. C. , Venkateswarlu P. 
Published: July 2007

AbstractDiscontinuities in the plot of the logarithm of the conductance versus reciprocal absolute temperature are observed at all the four phase transformations of cooled melts of RbNO3. This behaviour is explained in terms of the crystal structure of RbNO3.
“Fanning”‐Magnetization Reversal and Exchange Stiffness
Authors: Andrä W. , Brodkorb W. 
Published: July 2007

AbstractStarting from the method of Methfessel, Middelhoek, and Thomas [1] for the determination of the exchange stiffness, theoretical considerations are performed about the magnetization reversal in a ferromagnetic thin film with the easy magnetization direction in the plane of the film. The dependence of the magnetization directions on the parameters of the film on an inhomogeneous magnetic field to produce the “fanning”‐magnetization, and on an arbitrary homogenous magnetic field for the magnetization reversal is discussed. The knowledge of the deviation of the surface magnetization from the easy magnetization direction permits to determine the exchange stiffness.
The Excitation of Polarization Waves in Bound Electronic States
Authors: Hartley B. M. 
Published: July 2007

AbstractThe appearance of broad peaks in the electron energy loss spectra of elements in the first, second, and third long periods of the periodic table is discussed. It is shown that these peaks are similar to peaks which can be calculated by assuming absorption processes appropriate to ionization of bound states in these metals. By comparison with the calculated peaks and with the known optical constants of graphite a mode of excitation in the form of a collective polarization wave in these bound states is proposed. The possibility of deriving the optical constants of materials from their electron energy loss spectra is discussed.
Current Oscillations in GaAs under Acoustic Amplification Conditions. I. Experimental Study
Authors: Hugon P. Leroux 
Published: July 2007

AbstractCurrent oscillations, accompanied by the propagation of a high‐field domain, have been observed in piezoelectric semiconducting GaAs. The occurrence of oscillations has been found to depend on such parameters as crystalline orientation, length of the sample, temperature, concentration, and mobility of carriers. The characteristics of the high‐field propagating domain depend to a lesser extent on these parameters.
On Majority Carrier Sweep‐Out by Trapped Space Charge in Gold‐Doped Silicon
Authors: Lemke H. , Müller G. O. 
Published: July 2007

AbstractAfter pulsed majority carrier injection into gold‐doped p‐type Si, a decrease in conductivity occurs, which is caused by sweep‐out of free thermal carriers in the electric field of the trapped injected space charge. The step‐like recovery of conductivity (carrier concentration) is observed after a time comparable with the thermal release time of the traps. The dependence of depletion time on injection voltage or injected space charge was determined at various temperatures. The temperature dependence of injection voltages for zero depletion time reveals two regions in which different mechanisms of recovery are dominant. The results are in good agreement with a simple theory and values for the donor level of Au in Si ED = 0.315 eV and the cross section for holes \documentclass{article}\pagestyle{empty}\begin{document}$ S_{\rm p} = \frac{1}{g}2.5 \times 10^{ - 14} \,{\rm cm}^2 $\end{document} can be derived.
Space‐Charge‐Limited Currents in Vitreous Antimony Trisulfide Films
Authors: Budinas T. , Mačkus P. , Smilga A. , Viščakas J. 
Published: July 2007

AbstractFor vitreous antimony trisulfide films (thickness 6.4 to 16.1 μm) the steady‐state current‐voltage characteristics were measured. The current proportional to U2 d−3 are interpreted in terms of space‐charge‐limited currents (SCLC) with a single trap level. It is proved that a steep current increase at the end of the square‐law region is caused by trap filling. The values of the parameters of this trapping level calculated using two independent methods – from the temperature dependence of the reduction factor θ and from the trap‐filled limit (TFL) voltage – are in close agreement. The polarization the conduction mechanism of vitreous Sb2S3 films at lower temperatures are discussed.
Negative Magnetoresistance Anisotropy in Thin Magnetic Films
Authors: Kouritsyna E. F. , Vasilyev Yu. V. 
Published: July 2007

AbstractThe resistivity change of thin films of nickel and iron is investigated in planar magnetic fields above 4 kOe. After being saturated, the films exhibit negative slopes of different magnitude in the transverse and longitudinal resistivities. The observations at room temperature indicate essential thickness dependences of the Δϱ‐effect as well as of the slopes. A correlation method is used to prove it. In an attempt to give an explanation of the negative magnetoresistance anisotropy the d‐electrons have to be viewed as localized and itinerant at the same time.
Dispersion of the Refractive Indices and Birefringence of CdSxSe1−x Single Crystals
Authors: Lisitsa M. P. , Gudymenko L. F. , Malinko V. N. , Terekhova S. F. 
Published: July 2007

AbstractThe spectral dependence of the refractive indices and birefringence of CdSxSe1−x (including CdS and CdSe) single crystals has been investigated from the fundamental absorption edge up to the lattice vibration spectrum in the temperature interval 100 to 600 °K. In the region of v > 5000 cm−1 the measurements are carried out by the method of prism (with an absolute error for n of 5 × 10−4), for v < 5000 cm−1 by the modified interference method (with an absolute error for n of 5 × 10−3, and for Δn = ne − no of (2 to 4) × 10−5). The results are discussed.
Magnetic Anisotropy of FeNiCo Ferrites
Authors: Bryukhatov N. L. , Pakhomova N. L. , Kozlov V. A. , Potakova V. A. 
Published: July 2007

AbstractThis paper deals with the anisotropy induced by thermomagnetic treatment in mono crystals of Ni0.620 Co0.100 Fe Fe □0.004 O. The induced magnetic anisotropy has been studied and an explanation of this effect is proposed. For (100) and (110) planes the experimental data agree with the calculations.
Galvanomagnetic Properties of ZnxHg1−xTe Solid Solutions
Authors: Niculescu D. , Dziuba E. Z. 
Published: July 2007

AbstractAn investigation is made of the electrical conductivity and the Hall coefficient of ZnxHg1−xTe system with x = 0 and x = 0.2 as a function of the temperature and magnetic field in the ranges 77 to 400 °K and 250 to 1000 Gs, respectively. An effect of the “heavy carriers” on the galvanomagnetic properties is found. The additional conductivity due to these “carriers” has a temperature independent value. The energy gap for HgTe is estimated to Eg = −0.27 eV and Eg = −0.16 eV at the temperatures 77 and 300°K, respectively.
Majority Carrier Sweep‐out after Pulse Injection into Semiconductors
Authors: Lemke H. 
Published: July 2007

AbstractAfter the removal of majority injecting voltages on semiconductors with traps a sweep‐out of free carriers in the field of the trapped space charge occurs resulting in a subthermal population of the majority band. A simple model leads to a system of Abel type differential equations, a closed solution of which could not be found. A “quasi‐stationary” approximation adequate to the experimental conditions relates the prominent features as sweep‐out time, depleted concentration, and recovery time to physically significant parameters and gives evidence of two different mechanisms of recovery: at high temperatures (relative to the trap depth) a competition between sweep‐out and dielectric relaxation, at low temperatures competition between retrapping and sweep‐out.
Theory of Surface Elastic Wave Excitement in Semiconductors with Low Rate of Surface Recombination of Current Carriers
Authors: Vagner I. D. , Ioffe I. V. , Shender E. F. 
Published: July 2007

AbstractThe instability of quasi‐neutral waves in semiconductors with two types of current carriers in electric and magnetic fields at low surface recombination rate is studied theoretically. It is shown that this instability causes the excitation of Rayleigh waves even if the drift velocity is lower than the surface wave velocity.