bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reaction kinetics of stage III recovery in aluminium after neutron irradiation
Authors: Isebeck K. , Müller R. , Schilling W. , Wenzl H. 
Published: July 2007

AbstractLow temperature neutron irradiation of high purity aluminium (up to a dose of 7.2 × 1017 nvt) produces a resistivity change of Δϱ = 5 × 10−8 Ωcm measured at 90.2 °K. The recovery is studied for isochronal and isothermal annealing in the stage III temperature range from 180 to 263 °K. This entire recovery region is uniquely activated with an activation energy of (0.58 ± 0.02) eV. The recovery mechanism is found to be bimolecular, the initial recovery being due to the correlated recovery of defects situated at small relative distances in defect clusters. The last 50% of stage III follow second order kinetics. The capture volume for interstitial‐vacancy recombination can be determined from the measurements. The results support the theory that in stage III interstitial atoms migrate freely and recombine with vacancies.
On the formation of single crystal films of F.C.C. metals on alkali halide cleavage planes in ultrahigh vacuum
Authors: Kunz K. M. , Green A. K. , Bauer E. 
Published: July 2007

AbstractThin films of Au, Al, and Ag are evaporated in an ultrahigh‐vacuum reflection electron diffraction unit onto NaCl, KCl, and KI {100} surfaces cleaved in air and in situ. Their structure is studied by reflection diffraction during and after deposition, and by transmission electron diffraction microscopy. The results of simultaneous evaporation onto crystals with different surface condition (air versus vacuum cleaved) or composition show that the different stages of film growth (mainly nucleation and coalescence) depend in a complicated manner upon surface condition and composition. Electron irradiation prior and during deposition, preannealing of the air cleaved surface, and annealing of the film after deposition strongly influence the film structure.
Die kritische Schubspannung kubischer Kristalle mit Fehlstellen tetragonaler Symmetrie. III. Elektronen‐ und neutronenbestrahltes Aluminium sowie elektronenbestrahltes Kupfer
Authors: Frank W. 
Published: July 2007

AbstractAluminium enthält nach Elektronen‐ und Neutronenbestrahlung dispers verteilte Zwischengitteratome in der Hantelkonfiguration. Entsprechendes gilt für Kupfer nach Elektronenbestrahlung. Es wird gezeigt, daß der in diesen Fällen beobachtete Zuwachs der kritischen Schubspannung infolge von Bestrahlung quantitativ durch die kurzreichenden elastischen Wechselwirkungen erklärt werden kann, welche die Versetzungen mit Zwischengitteratomen in unmittelbarer Nähe ihrer Gleitebenen besitzen.
The geometry of charged dislocations in the NaCl structure
Authors: Brantley W. A. , Bauer Ch. L. 
Published: July 2007

AbstractVarious dislocation configurations are examined in the NaCl structure for the presence of localized electrostatic charge assuming slip systems of the {110} 〈110〉 type. Pure edge and screw dislocations do not display an effective electrostatic charge. However, edge dislocations that possess a jog length of a √2/4 or an abrupt kink length of a √2/8 display a virtual charge of ± q/2 whereas edge dislocations that possess a jog length of a √2/2 or an abrupt kink length of a √2/4 are electrically neutral (a is the lattice parameter and q is the ionic charge). Similarly, screw dislocations that possess a jog length of a √2/4 or an abrupt kink length of a/4 display a virtual charge of ±q/2 whereas screw dislocations that possess a jog length of a√2/2 or an abrupt kink length of a/2 are electrically neutral. Either type of jog can be formed on a dislocation, but charged kinks must occur in electrically neutral pairs. Intersection between dislocations on orthogonal slip planes yields only neutral jogs whereas intersection between dislocations on oblique slip planes yields only charged jogs and neutral kinks. Nodes formed by the intersection of n edge dislocations display a virtual charge of ±q/2 whenever n is odd (n ≠ 1) and are electrically neutral otherwise. The emergence point of a dislocation on an atomically flat surface always is neutral although the point may acquire a charge of ±q by ion transport. In general, the presence of a charge of ±q/2 denotes an infinite source (or sink) for anion and cation vacancies whereas a charge of ±q denotes an expendable source.
Der Einfluß von überschüssigem antistrukturellem Bi auf die Wärmeleitfähigkeit des Kristallgitters von Bi2Te3, Bi2Te3‐Sb2Te3 und Bi2Te3‐Bi2S3 mit Jodbeimischung
Authors: Kutasov V. A. , Smirnov I. A. 
Published: July 2007

AbstractDer Wärmewiderstand von Jod‐dotiertem Bi2Te3, Bi2Te3‐Sb2Te3 und Bi2Te3‐Bi2S3 wird gemessen. Es wird festgestellt, daß das Additivitätsgesetz für den Wärmewiderstand der durch die Jodbeimischung hervorgerufen wird, nicht erfüllt ist. Die Abweichung von diesem Gesetz ist durch das Vorhandensein von überschüssigem Bi in dem untersuchten Material zu erklären, das antistrukturell die Te‐Plätze einnimmt.
Electrical resistivity and longitudinal electrical magnetoresistivity of palladium‐rich palladium‐erbium alloys at low temperatures
Authors: Arajs S. , Dunmyre G. R. , Dechter S. J. 
Published: July 2007

AbstractElectrical resistivity of palladium‐erbium alloys, containing 0.50, 1.00, 1.93, 3.97, 5.22, and 6.63 at% erbium, have been studied between 4 and 40 °K. In spite of localized magnetic moments on erbium atoms, no anomalies of any type are observable in the electrical resistivity curves. These palladium‐erbium alloys approximately obey the Matthiessen rule. Longitudinal magnetoresistivity measurements at 4.2 °K in fields up to 60 kOe have been made on the same alloys. The total longitudinal magnetoresistivity rapidly decreases from positive values to zero values with increasing erbium concentrations. The magnetoresistivity for 5.32 and 6.63 at% erbium alloys is essentially zero at any magnetic field value. The change in the magnetic component of the total resistivity has been found to be extremely small. The electrical resistivity increase due to 1 at% erbium in palladium is about 2.9 μΩcm.
Anisotropy of the photoemission from some coloured alkali halides
Authors: Petrescu P. , Gheordânescu V. 
Published: July 2007

AbstractCrystals of coloured alkali halides showing dichroism display a marked anisotropy in the photoemission stimulated by polarized light. The results obtained by a new experimental technique are discussed and compared with those obtained for anisotropic colour centres by conventional optical methods.
Über ein Modell zur Berechnung der Entmagnetisierungskurven von Hartferriten
Authors: Heinecke U. 
Published: July 2007

AbstractEs wurde die Ausdehnung von Strontiumferritkristallen in Richtung der hexagonalen Achse und senkrecht dazu durch Ausmessen einer großen Anzahl von Körnern auf Schliffbildern anisotroper Strontiumferritmagnete bestimmt. Als Modell für den Magneten wird ein aus verkürzten Rotationsellipsoiden dieser Abmessungen zusammengesetztes Aggregat angesehen. Für die innere Feldstärke erhält man dann einen positiven Wert. Die Berechnung des Anfangsteils der Entmagnetisierungskurve kann auf den Fall einer kettenförmigen Anordnung der Teilchen reduziert werden.
Identification and morphology of oxide particles in internally oxidized Cu–Mn alloys
Authors: Howling D. H. 
Published: July 2007

AbstractElectron microscopy of internally oxidized Cu—Mn alloys has established that the dominant oxide formed is MnO (manganosite). This was confirmed by X‐ray measurements. The presence of γ‐Mn2O3 (γ manganese sesquioxide) and Mn3O4 (manganese spinel) have also been identified. The morphology and orientation of the oxide particles shows that the preferred growth form is of cubic shape, the oxide particles maintaining crystallographic continuity with the Cu matrix.
Bestimmung der Stapelfehlerenergie kubisch‐flächenzentrierter Metalle aus der Analyse des elektronenmikroskopischen Beugungskontrastes von Stapelfehlerdipolen
Authors: Häussermann F. , Wilkens M. 
Published: July 2007

AbstractIn der vorliegenden Arbeit wird aus dem elektronenmikroskopischen Beugungskontrast von Stapelfehlerdipolen in verformten kubisch‐flächenzentrierten Metallen die spezifische Stapelfehlerenergie bestimmt. Der elektronenmikroskopische Beugungskontrast von Stapelfehlerdipolen wurde in Abhängigkeit von der Geometrie des Stapelfehlerdipols und von verschiedenen Parametern (Tiefe, Anregungsfehler, Foliendicke) berechnet. Auf Durchstrahlungsaufnahmen von Kupfer, Gold, Silber, Nickel und Nickel‐Kobalt‐Legierungen wurden Stapelfehlerdipole gefunden und deren Kontrastbreiten gemessen. Aus der maximalen Kontrastbreite kann man mit Hilfe der Ergebnisse unserer Kontrastrechnungen und der Stabilitätsberechnungen von Seeger und Wobser [17] obere Grenzen der Stapelfehlerenergien angeben. Es ergaben sich die Werte: γCu = 59 erg/cm2, γAu = 42 erg/cm2, γAg = 22 erg/cm2, γNi = 180 erg/cm2, γNi‐40% Co = 78 erg/cm2, γNi‐60% Co = 49 erg/cm2, γNi‐67% Co = 47 erg/cm2.
Der g‐Faktor von F‐Zentren in Alkalihalogenid‐Kristallen
Authors: Schmid D. 
Published: July 2007

AbstractDer g‐Faktor von F‐Zentren in 15 verschiedenen Alkalihalogenid‐Kristallen wurde mit Elektronenspinresonanz bei 24000 MHz gemessen. Die Abweichungen Δg vom g‐Faktor des freien Elektrons liegen zwischen 5 × 10−4 (LiF) und 5,3 × 10−2 (RbJ). Diese Abweichungen können an Hand eines von Adrian vorgeschlagenen Modells gedeutet werden: Das ungepaarte Elektron ist im elektrischen Feld der Nachbarkerne einer Spin‐Bahn‐Wechselwirkung ausgesetzt. Die numerische Berechnung der g‐Faktor‐Verschiebung wird durch die Verwendung der gemessenen anisotropen Hyperfeinstruktur‐Konstanten b sehr erleichtert. Man erhält befriedigende Übereinstimmung zwischen den berechneten Werten und den Meßwerten, wenn die nächstbenachbarten Kationen den Hauptbeitrag zur g‐Faktor‐Verschiebung liefern. Die Übereinstimmung wird schlechter, wenn der Beitrag der Anionen stärker ins Gewicht fällt. Bei ausgerichteten Lithium‐FA‐Zentren in KCl wurde eine Anisotropie des g‐Faktors beobachtet, deren Wert g⟂ − g∥ = (11 ± 4) × 10−4 innerhalb der Fehlergrenzen mit dem theoretisch erwarteten Wert von 9 × 10−4 übereinstimmt.
The effective mass of electrons in (InSb)x·(InTe)1−x crystals
Authors: Molodyan I. P. , Nasledov D. N. , Radautsan S. I. , Sidorov V. G. 
Published: July 2007

AbstractMeasurements of the thermoelectric power, transverse Nernst‐Ettinghausen effect, conductivity, and Hall effect allow the concentration and temperature dependence of the electronic effective mass m* to be calculated for crystals of the solid solution (InSb)x(InTe)1—x (for × = 1 to 0.85) in the temperature range 100 to 370 °K. Solid solutions having × > 0.99 (I) behave like InSb doped with tellurium, and crystals of this type having electron concentrations (n) greater than 2 × 1018 cm−3 show an m* (n) dependence which differs from that predicted by Kane. Solid solutions with x ≦ 0.99 (II) show a different temperature dependence of m* from those with x > 0.99.
Thermally activated motion of screw dislocations in B.C.C. metals
Authors: Vítek V. 
Published: July 2007

AbstractThe splitting of a 1/2 〈111〉 screw dislocation on one and three {110} planes, and on one and two {112} planes is assumed. It is proposed that repeated mutual transformations of these splittings during the motion of a screw dislocation control its thermally activated motion. Activation energies of these transformations are calculated as functions of the stacking fault energy, the external shear stress, and the orientation of the maximum resolved shear stress plane. The velocity of a screw dislocation is then calculated by the usual rate theory.
Dislocation theory of slip geometry and temperature dependence of flow stress in B.C.C. metals
Authors: Vítek V. , Kroupa F. 
Published: July 2007

AbstractIt is assumed that transformations of the splitting of a screw dislocation are continually repeated during its motion, and thus the screw dislocation crosses into different {110} and {112} planes [1]. On the basis of this mechanism a theory of the composite slip on {110} and {112} planes is established, and the dependence of the orientation of the slip plane on the orientation of the maximum resolved shear stress plane is calculated. The results are compared with the measurements of Taoka et al. [8] and Šesták and Zárubová [9]. Further it is shown that the same mechanism can account for the strong temperature dependence of the flow and yield stress.
Point defect electron scattering in Beryllium
Authors: van Torne L. I. 
Published: July 2007

AbstractThe dc resistivity due to electron scattering from a vacancy, an octahedral interstitial, and a tetrahedral interstitial in beryllium was computed by application of the diffraction model concept of pseudopotentials in the theory of metals. The resistivity values corresponding to one atomic percent concentration of each defect type are: octahedral interstitials, 0.283 μΩ cm; vacancies, 0.296 μΩ cm; and tetrahedral interstitials, 0.249 μΩ cm.
Piezowiderstand von p‐Germanium
Authors: Asche M. , Sarbej O. G. , Vasetskii V. M. 
Published: July 2007

AbstractEs wurde der Piezowiderstand von p‐Germanium als Funktion des Druckes und der Verunreinigungskonzentration bei 77 und 300 °K gemessen. Die experimentellen Resultate zeigen, daß der Piezowiderstand von beiden Größen stark abhängt. Die Daten für kleine Drücke stimmen gut mit der Theorie der linearen Effekte überein, für höhere Drücke überwiegen die quadratischen Glieder.
Note on relaxation effects in Mössbauer spectra
Authors: van Zorge B. C. , Caspers W. J. , Dekker A. J. 
Published: July 2007

AbstractA comparison is made between the van der Woude‐Dekker and Wegener models describing the effect of relaxation on the Mössbauer line shape. It is shown that both models lead to indentical basic formulae for the Mössbauer spectrum in terms of autocorrelation functions of the atomic spin. The approximation for short ion spin correlation times is discussed using a more general method than that used by Wegener.
The crystalline structure of ZnTe thin films
Authors: Spînulescu‐Carnaru I. 
Published: July 2007

AbstractThe crystalline structure of ZnTe thin films is studied as a function of stoichiometric and growth conditions. A determination is made of the optimum conditions for producing ZnTe thin films with pure hexagonal structure. The lattice constants of cubic and hexagonal ZnTe cells are computed.
Abhängigkeit des Supraleitverhaltens tordierter Niobeinkristalle vom Probendurchmesser
Authors: Nembach E. , Freyhardt H. , Haasen P. 
Published: July 2007

AbstractAn 〈110〉 orientierten Niobeinkristallen wurden Versetzungsdichte und magnetische Hysterese im supraleitenden Zustand als Funktion des Torsionswinkels für ca. 3 und 4 mm starke Proben gemessen.
Ein hochauflösendes Verfahren zur Untersuchung magnetischer Strukturen von Supraleitern
Authors: Träuble H. , Essmann U. 
Published: July 2007

AbstractMagnetische Strukturen von supraleitenden oder ferromagnetischen Materialien können durch Verdampfen ferromagnetischer Substanzen in Heliumatmosphäre sichtbar gemacht werden. Das Verfahren zeichnet sich durch hohe Auflösung aus. Die Strukturen können lichtmikroskopisch und elektronenmikroskopisch (Replikaverfahren) beobachtet werden. Als Beispiel wurde der Zwischenzustand von supraleitendem Blei untersucht.
The rate of twin layer growth in bismuth single crystals
Authors: Startsev V. I. , Soldatov V. P. , Brodsky M. M. 
Published: July 2007

AbstractThe stress dependence of the normal and tangential rate of twinning is determined in bismuth single crystals of different purities. On the basis of experimental data it is concluded that the broadening of twin layers occurs by a heterogeneous mechanism. The activation volumes defining the processes of twin layer broadening and twin growth in the shear direction are determined. It is established that the process of twin layer broadening in bismuth involves the simultaneous reorientation of about 104 atomic planes and in each plane 10 to 102 twinning dislocations participate per centimetre length of twin plane in the shear direction.
Magnetic properties of Ce, Pr, and Nd monochalcogenides at 4.2 to 1300 °K
Authors: Smolenskii G. A. , Zhuze V. P. , Adamyan V. E. , Loginov G. M. 
Published: July 2007

AbstractThe magnetic properties of Ce, Pr, and Nd monochalcogenides are studied over a wide temperature range. The magnetic measurements at elevated temperatures show that the 4f electrons of metal ions are localized and their number is equal to that of the free tripositive metal ions. At low temperatures all the compounds investigated exhibit magnetic ordering except PrSe and PrTe. The possible types of magnetic ordering, and a mechanism for the exchange interaction, are discussed.
Change of the deformation mechanism (slip ⇄ twinning) in polycrystalline α‐iron
Authors: Moiseev V. F. , Trefilov V. I. 
Published: July 2007

AbstractThe conditions for the change of the deformation mechanism (slip ⇌ twinning) are investigated in the temperature range from −185 to 20 °C at the deformation rate . It is found that the strength parameters may be expressed by the Petch equation σ = σ0 + Kd−1/2 for twinning and slip deformation. The temperature dependence of the “frictional” stress and the term K for twinning are studied experimentally. The observed temperature dependence of the slope K is discussed in terms of stress relaxation near stress concentrations. The temperature dependence of the resolved twinning stress is determined by considering the stress concentration necessary for the start of a twinning source. An approximate expression is obtained for estimating the stacking fault energy from the temperature dependence of the yield stress of b.c.c. metals.
Small Angle Electron Scattering from Vacuum Condensed Metallic Films I. Theory
Authors: Wade R. H. , Silcox J. 
Published: July 2007

AbstractWe present the basis of a kinematic theory to account for electron diffraction effects from discontinuous vacuum condensed metallic films in which the separate particles act as scattering centres. The diffraction image depends on the variation in the interparticle spacings and is repeated in several layers of reciprocal space. The treatment is valid for any paracrystalline object.
Small Angle Electron Scattering from Vacuum Condensed Metallic Films II. Experimental Results
Authors: Wade R. H. , Silcox J. 
Published: July 2007

AbstractThe electron microscope is used as a small angle diffraction camera, with an angular resolution of about 5 × 10−6 rad, to investigate the structure of some vacuum deposited metallic films. Film structure is sensitive to condensation rate and radiant heat received from the vapour source. The growth of crystallites as separate columns is favoured by slow condensation rates in the case of nickel, permalloy, and palladium whilst at faster rates the films become continuous at an earlier stage in their growth. The sensitivity of the diffraction effects on the film structure is demonstrated and the general relations proposed in Part I are verified.
On the Theory of Interfacial Energy and Elastic Strain of Epitaxial Overgrowths in Parallel Alignment on Single Crystal Substrates
Authors: Jesser W. A. , Kuhlmann‐Wilsdorf D. 
Published: July 2007

AbstractRefined expressions, amendable to experimental testing, for the equilibrium elastic strains in epitaxial overgrowths are derived, based on earlier theories by van der Merwe and Cabrera. Continuous films as well as isolated nuclei on substrates are considered.
Piezo‐Hall Effect in n‐Type Germanium
Authors: Walton A. K. , Eyoku G. J. O. 
Published: July 2007

AbstractThe piezo‐Hall effect has been measured at room temperature in germanium specimens doped with ≈︁1015 and ≈︁1018 Sb atoms per cm3. An experimental arrangement was used in which the stress and magnetic field were along a 〈111〉 valley symmetry direction and the current and Hall probes in the normal plane. The experimental results for ≈︁1018 cm−3 material are in accord with the simple electron transfer model with a mobility anisotropy of 7. The ≈︁1015 cm−3 material shows an anomalously small variation of Hall coefficient with stress. Possible explanations in terms of constancy of the net carrier concentration and intervalley scattering are discussed and rejected.
Verformungs‐ und Temperaturabhängigkeit der Magnetisierungsprozesse in Nickeleinkristallen I. Blochwandverschiebungen in 〈110〉‐ und 〈111〉‐Nickeleinkristallen
Authors: Köster E. 
Published: July 2007

AbstractDie Magnetisierung und magnetostriktive Längenänderung stabförmiger Nickeleinkristalle wurde in Abhängigkeit von der plastischen Verformung und der Temperatur gemessen. Die Bereichsstruktur parallel zur 〈110〉‐ bzw. 〈111〉‐Stabachse entmagnetisierter Nickeleinkristalle besteht aus acht Phasen. Die vier zur Stabachse des 〈110〉‐Kristalls senkrecht magnetisierten Phasen nehmen 60%, die beiden parallel und antiparallel zur Stabachse des 〈111〉‐Kristalls magnetisierten Phasen nehmen 30% des Kristallvolumens ein. Die Phasenvolumina sind unabhängig vom Verformungsgrad und von der Temperatur. Bei 77°K sind die Koerzitivfeldstärke und die Anfangssuszeptibilität durch 180°‐Wandverschiebungen bestimmt, mit zunehmender Temperatur spielen Drehungen eine wachsende Rolle.
On the Kinetics of Short‐Range Ordering in AuAg (50,50) and CuAl (85,15)
Authors: van Den Beukel A. , Coremans P. C. J. , Vrijhoef M. M. A. 
Published: July 2007

AbstractThe establishment of short‐range order in the alloys AuAg (50,50) and CuAl (85,15) is investigated by electrical resistivity measurements on quenched wires. The kinetics of the process can be described by two equations based on the following assumptions: 1. The rate of ordering is proportional to the deviation from equilibrium order and to the number of vacancies. 2. The quenched‐in vancancies disappear by first order kinetics. 3. The activation energy Q of vacancy migration depends on the degree of order. During ordering Q appears to increase by a few hundredths of an eV in both alloys.
Interpretation of Deviating Points in the Relation between the Rate of Crystal Growth and the Relative Supersaturation
Authors: Bennema P. , Kern R. , Simon B. 
Published: July 2007

AbstractA special weighing technique may be used to determine the rate of crystal growth R as a function of the relative supersaturation σ for growth from an aqueous solution [1, 2]. It is found that R is proportional to σ for potassium aluminium alum with 10−4 ⪅ σ ⪅ 10−2[1,3] but that for σ ⪆ 10−2 deviations occur from the linear form. In the present work these deviations are explained by assuming that a two‐dimensional nucleation mechanism and a spiral grooth mechanism occur simultaneously.
The Study of Defects in Quenched Nickel
Authors: Mughrabi H. , Seeger A. 
Published: July 2007

AbstractQuenched nickel foils are investigated by electrical resistivity measurements, X‐ray small‐angle scattering and transmission electron microscopy. A marked dependence of the annealing behaviour on the purity of the specimens and the quenching atmosphere is observed. The quenched‐in vacancy concentrations are rather low, particularly in pure specimens where the total quenched‐in vacancy concentration is less than 5 × 10−6. In pure specimens one recovery stage only, centred at about 110°C, is observed between room temperature and 750°C. In less pure specimens a similar recovery stage is followed by a pronounced stage IV recovery (270°C) and a complex annealing behaviour above 400°C. The migration energies of mono‐ and divacancies are determined as E1VM = (1.4±0.05) eV and E2VM ⪆ (0.72±0.07) eV respectively. The divacancy binding energy is estimated as E2VM > 0.23 eV. This rather large value is thought to be responsible for substantial vacanxcy losses during quenching.