bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasma Wave Resonances in Positive Ions Under the Surface of Liquid Helium
Authors: Hannahs Scott , Williams Gary A.
Published: March 2014

Plasma wave resonances are studied in a two-dimensional plasma of positive ions confined just below the surface of liquid helium. The resonances are observed over the range from 14 mK to 400 mK at ion densities up to 1×108/cm2. The resonant frequency is determined by the ion effective mass, and the line width measures the scattering from the excitations of the helium surface. Strong coupling of the ions to the ripplons is evidenced by a rapid increase of the line width as the perpendicular electric field is increased to the surface. Comparison with the theory of Shikin and Monarkha [1] is presented. The Wigner crystallization transition has been searched for, but no change in the plasma wave characteristics has been observed over the range 20<Γ<2000, where Γ is the ratio of Coulomb energy to kinetic energy.
Ripplon Scattering from Two-Dimensional Electron Arrays at the Melting Point
Authors: Stan M. A. , Dahm A. J.
Published: March 2014

The variation of the electron effective mass and the rate of ripplon scattering from the electron array are studied a function of temperature. A qualitative discussion of these results is given within the framework of the dislocation-mediated melting theory.
Mobility of Electrons on Helium Films
Authors: Jiang H. W. , Dahm A. J.
Published: March 2014

Mobilities of two-dimensional arrays of electrons on helium films supported by a glass substrate were measured as a function of temperature at various densities and film thicknesses. Results are in reasonable agreement with those of other workers when fit to an empirical formula of Platzman and Iye. The temperature dependence of the scattering in excess of theory places severe constraints on explanations of excess scattering.
Nonlinear Properties of Plasma Wave Resonances in Ions under the Helium Surface
Authors: Hannahs Scott , Greenfield Alan , Williams Gary A.
Published: March 2014

A variety of nonlinear effects are observed in plasma wave resonances of positive ions held just below the liquid helium surface. At high drive amplitudes the resonance curves “backbend” to lower frequencies, and become hysteretic. There is also a nonlinear increase in the dissipation resulting in a broadening of the tuning curves. The generation of second and third harmonics of the fundamental have been observed using FFT analysis, with the third harmonic being unexpectedly strong. Over narrow ranges of drive amplitude and frequency there are sharp onsets of sideband formation, where frequencies differing by a few kilohertz from the drive appear in the response.
High Field Magnetization of a Doped DM Spin Glass Alloy
Authors: Yao Kai-Lun , Liu Zu-Li
Published: March 2014

In this paper we study the high field magnetization and saturation, and the effect of DM interaction on magnetization for CuMn spin glass doped with impurities. The results indicate a scaling behavior of magnetization by concentration. It is shown that the magnetic field for saturation is proportional to the concentration of magnetic ions but is not related to the doped impurities.
Mean Field Behavior of Anisotropic Spin Glass Fe2TiO5
Authors: Srivastava J. K. , Hammann J.
Published: March 2014

The H-T phase diagram, critical (scaling) behaviour and magnetisation - time dependence are reported in the uniaxially anisotropic spin glass pseudobrookite (Fe2TiO5); 3≦T≦80K. It is seen that most of the results agree with the mean field predictions.
Dipole Glass in Hydrogen-Bonded Mixed Crystals
Authors: Matsushita Eiko , Fuchizaki Kazuhiro
Published: March 2014

In hydrogen-bonded mixed crystals of ferro- and antiferroelectrics, Rb1-x(NH4)xH2PO4, the structures of glass state at the intermediate x region are demonstrated by means of 2D-Monte Carlo simulation. At low temperature, protons rearrange themselves to fulfill the ice rule condition, and produce the glass structure resulting from the competition between two kinds of proton ordering.
Two Level Tunneling Systems in the Glasslike Phase of Rb1-x(NH4)xH2PO4 at Low Temperatures
Authors: Miura Y. , Takashige M. , Terauchi H. , Sugiyama S. , Mamiya T.
Published: March 2014

The dielectric constants of the mixed crystals of ferroelectric RbH2PO4 and antiferroelectric NH4H2PO4 have been measured down to 20 mK. The temperature dependence of the dielectric constant for x=0.9, in the antiferroelectric phase, shows no anomaly. The results in the glasslike phase, however, show the frequency dependent minimum, which Is the universal property in amorphous solids, explained by the existence of two level tunneling systems (TLS). Our results show that the origin of TLS In the glasslike phase is not the structural disorder but the random configuration of the electric dipoles.
The Specific Heat of the Amorphous and Crystalline States of the Monomer DGEBA between 1.4 and 20 K
Authors: Collocott S. J. , Rosenberg H. M.
Published: March 2014

Measurements of the specific heat, Cp, in both the amorphous and the crystalline states, of the monomer of epoxy-resin, diglycidyl ether of bisphenol A, have been made between 1.4 and 20 K. There is a marked difference in the results for the two states. Whilst both sets of data show a maximum in the plot of Cp/T3 versus T, the maximum for the amorphous material is at 4.5 K whereas it is at 6.5 K for the crystalline sample. These results are in good agreement with the predicted behaviour of the specific heat for this material in the two states as deduced from inelastic neutron scattering measurements by Dianoux, Page and Rosenberg (Phys. Rev. Letters 58, 886 (1987)).
Magnetic Suceptibility of the Compounds (DyxY1-x)2Mo2O7
Authors: Raju N. P. , Rangarajan G. , Srinivasan R.
Published: March 2014

In the Rare-Earth Molybdenum Pyrochlores RE2Mo2O7 two types of magnetic ions are present, namely RE3+ and Mo4+. To see if there is any magnetic interaction between the two types of ions, magnetic susceptibility of the compounds (DyxY1-x)2Mo2O7 was measured for x = 0.2, 0.4, 0.6, 0.8 and 1.0 in the range 300-2K at 83Hz. If we take the difference in the magnetic susceptibility values of the compounds as a function of temperature for Δx=0.6, we get three curves which are identical within the limits of the experimental error. This shows that the difference in the magnetic susceptibility is only due to the Dy3+ and its interaction with Mo4+ is weak. The magnetic moment of the Dy3+ obtained from a Curie-Weiss plot of the above results is 10.09 µB which compares with the value 10.64 µB for the free ion and 9.96 µB for the Dy3+ ion in Dy2Ti2O7.
Spatial Variation of Superconducting Gap: STM Measurements for NbN
Authors: Raider S. I. , Kirtley J. R. , Feenstra R. M. , Fein A.
Published: March 2014

A low temperature scanning tunneling microscope [1] was used to study the relationship between NbN film properties and topographic structure by simultaneously measuring the surface topography and the spatial variation of the superconducting energy gap. The images show significant variation of the energy gap with position. Regions with no superconducting energy gap arise when magnetic fields of 6 Tesla are applied and some evidence of a correlation between the surface and energy gap topography appears.
Electrical Resistivity of Transition Metal Substituted Y9Co7 Compounds
Authors: Ranganathan R. , Thummes G.
Published: March 2014

The resistivity of a series of Y9Co7 compounds containing transition metal Lu, Gd, Ni, Zr, Ti has been measured from 4 to 300K. The results are discussed in terms of parallel resistor model, s-d scattering and diffraction model. Also, we report the evidence of spin-fluctuation effect in the resistivity of these compounds (ex. Gd substituted Y9Co7 and the data may be scaled into a universal curve proposed by Kaiser and Doniach.
A 153Eu NMR Study of EuSe at Ultralow Temperatures
Authors: Okada K. , Fujii M. , Kawano K. , Lutgemeier H. , Pieper M. , Zinn W.
Published: March 2014

153Eu NMR of EuSe is studied at very low temperatures using a 3He-4He dilution refrigerator. Below 1.8K the free induction decay(A-signal) which comes from the 153Eu nucleus in the antiferromagnetic state is observed without external field. In the small external field the signal (B-signal) which comes from the nucleus in the ferrimagnetic state grows up and at 0.05 Tesla the intensity of A-signal is equal to that of B-signal. In the field between 0.15 and 0.4 Tesla only B-signal is observed and by double nuclear magnetic resonance it is found the B-signal is modified by frequency pulling effect.
Evidence for a One Dimensional Indirect Interaction between Localized Moments in Copper Phthalocyanine Iodide Mediated by Itinerant Electrons
Authors: Ogawa M. Y. , Liu S. , Hoffman B. M. , Lee M. , Lee S. , Yudkowsky M. , Lovellette M. , Halperin W. P.
Published: March 2014

Measurements on Copper phthalocyanine iodide Cu(pc)I indicate that this material is an excellent one dimensional conductor with parallel arrays of localized moments that interact strongly with the conduction electrons. The result is an antiferromagnetic indirect interaction between localized spins mediated by the itinerant electrons. A comparison is made between ESR, magnetic susceptibility, and NMR measurements for a number of materials with the phthalocyanine architecture: Ni(pc)I, Cu(pc) and Cu(pc)I.
Mössbauer Study of the Trinuclear Clusters in [Fe3
3+MO(O2CR)6L3]X (M=Mn2+, Fe3+, and Ni2+)
Authors: Takano Mikio , Shinjo Teruya , Blake Antony B.
Published: March 2014

The antiferromagnetic nature of the intracluster interactions in the title compounds gives rise to the ground state characterized by cluster spin of S = 3/2, 1/2, and 1 for M = Mn, Fe, and Ni, respectively. The spin polarization of the Fe3+ ions was measured by the Mössbauer effect. For the M = Mn and Fe compounds, measurements were extended to 0.04 K by using a 3He-4He dilution refrigerator. Slowing down of the cluster spin relaxation and an antiferromagnetic ordering due to intercluster interactions were observed for the M = Mn and Fe compounds, respectively.
Heat Transfer with LHe II Gorter-Mellink Flow In Porous Composite Materials
Authors: Wang Hulling , Li Qing , Guo Fangzhong
Published: March 2014

This paper is concerned with the characteristics of heat transfer with superfluid helium Gorter-Mellink flow in porous composite materials (diameter of channel 80µm, diameter of wire 15µm). The mathematical model is established and the results of calculation have been sorted out by dimensionless numbers. Experimental investigations were made by realizing stable transverse heat transfer with superfluid helium Gorter-Mellink flow and the transverse effective thermal conductivity is measured. This work is of great significance for the cooling of large superconductive magnets as well as for deep space information technology.
NMR of Oriented 54Mn in the Quasi-2 Dimensional Ferromagnet Mn(COOCH3)2·4H2O
Authors: Legros M. , Turrell B. G. , Kotlicki A.
Published: March 2014

NMR of oriented 54Mn nuclei has been observed in the quasi-2 dimensional ferromagnet Mn(COOCH3)2·4H2O. NMRON lines corresponding to the dominant m=-3→-2 transitions at ν1=434 MHz and ν2=476 MHz are attributed to the two manganese sites. The splitting of the lines and their field dependence is consistent with a magnetic pseudoquadrupole interaction of strength approximately 1 MHz. The HWHM line width is 0.25 MHz, a relatively large value for the very dilute 54Mn spins.
Two-Dimensional Heisenberg Ferromagnet
Authors: Takahashi Minoru
Published: March 2014

Low-temperature thermodynamics of Heisenberg ferromagnet on square lattice are analyzed by the use of modified spin-wave theory. In this system the susceptibility diverges as exp
(4πJS2/T). Pre-exponential factors are also calculated both for quantum and classical cases. The results are compared with those of renormalization group Monte Carlo method. Two-point correlation function and energy are calculated. The spin-wave results agree excellently with Monte Carlo calculation for finite systems.
Low-Temperature Amplitude-Dependent Internal Friction of Dislocation-Point Defect Systems
Authors: Kosugi Toshio , Kino Takao
Published: March 2014

To investigate the interaction between a dislocation and an impurity atom at low temperatures, amplitude-dependent internal friction (ADIF) measurements are made at 1.6 - 30 K by using pure Al crystals, into which are introduced a single kind of impurities, i.e., 100 at ppm Zn, 50 at ppm Ag, 25 at ppm Mg and 20 at ppm Cu, respectively. The following common features are found for all crystals: The applied stress amplitude σ0 under a constant ADIF varies as - T2/3 at lower temperatures, i.e., σ0/σ0(T=0)≧0.65, where σ0(T=0) is the extrapolated value; and the temperature dependence at σ0/σ0(T=0)≦0.87 is explained satisfactorily by a simple potential where the Cottrell type one is modified. From these results, the expected behavior on the dislocation motion at very low temperatures is briefly discussed.
Flow Structure of Thermal Counterflow Jet
Authors: Yamazaki Tsutomu , Murakami Masahide , Ichikawa Naoki , Nakai Hirotaka
Published: March 2014

The flow structure of a thermal counterflow jet in otherwise quiescent He II is investigated by the application of the method of flow visualization and with a laser Doppler velocimeter. Flow visualization pictures show the evolution of the jet patterns from laminar to turbulent ones and the existence of a large scale entrainment into a jet. The LDV measurement gives the velocity distribution and the velocity fluctuation of the normal component at a point.
Order to Order Crystalline Phase Transition Lattice Model
Authors: Wong K. W. , Wang D. M.
Published: March 2014

In this paper we show how to generate a continuous transformation between discrete point groups, and apply it to a simple two-dimensional lattice. The eigenvalues for this simple model is explicitly given in terms of the mapping generator. By minimizing the Free-energy in terms of the mapping generator, we find the stable lattice mode at all temperature. The critical exponent for the phase transition from a square lattice to a hexagonal lattice is obtainable numerically if we assume a constant density and a specific inter-ionic potential form.
Observation of the Pressure Dependence of Nonlinear Interactions in a Focused Coherent Acoustic Beam in Superfluid Helium
Authors: Wright D. R. , Hadimioglu B. , Jr. L. J. La Comb, , Quate C. F. , Foster J. S.
Published: March 2014

We have studied the saturation and stimulated decay of an 8 GHz focused acoustic beam in superfluid helium near 50 mK. Because the dispersion is a function of pressure, there are various regimes where different nonlinear processes dominate. At low pressures (upward dispersion) parametric self-enhancement of the noise causes rapid signal depletion. At intermediate pressures (linear dispersion) harmonic formation leads to saturation (a “shock wave”). At still higher pressures (downward dispersion) the power in the main focus far exceeds the shock onset threshold before depleting rapidly in what appears to be a four-phonon parametric enhancement of the spontaneous decay. We believe this to be the first experimental evidence of four-phonon parametric mixing in acoustics.
An Ordering Transition in the Turbulent Flow of Helium II
Authors: Krysac L. C. , Graham G. M.
Published: March 2014

High speed movies (3000 Frames/sec) of a high velocity planar jet of superfluid forced through a sharp tipped orifice will be shown. It will be seen that such a jet undergoes a reversible transition from turbulent flow at low velocity and heat flux, to quiescent flow at higher velocity and heat flux. The velocity, heat flux, and geometrical characteristics of this transition are discussed.
Fermi Liquid Corrections in the Theory of Type-II Superconductors
Authors: Gonczarek Ryszard
Published: March 2014

The problem of incorporating the Fermi liquid corrections into the theory of type-II superconductors in the presence of paramagnetic effects is considered. The Ginzburg-Landau parameter and Gibbs free-energy difference are derived as functions of Landau parameters F1
s and F0
a. Connections among magnetic properties of the normal and superconducting phases are defined and discussed.
Sheath Critical Field Hc3 of Layered Superconductors
Authors: Takanaka Kenji
Published: March 2014

The sheath critical field Hc3 parallel to the layers is calculated in the dirty layered superconductors. Since the depairing effect due to the orbital diamagnetism is expressed by the eigenvalue of a differential equation for the superconducting order parameter, we solve numerically the equation and express the eigenvalue in terms of the magnetic field. Using the relation between the eigenvalue and the magnetic field, and modifying the expression which Werthamer, Helfand and Hohenberg derived to study the upper critical field Hc2, we evaluate the temperature dependence of Hc3.
Phase Transitions between Type-I, Type-II/1 and Type-II/2 Superconductivity
Authors: Weber H. W. , Botlo M. , Sauerzopf F. M. , Wiesinger H. , Klein U.
Published: March 2014

In order to study the nature of phase transitions along the magnetization curve of low-κ superconductors, several Ta-, Nb- and V- single crystals of varying impurity content and, hence, different Ginzburg-Landau parameter κ (Tc) were investigated. The results are compared with recent microscopic calculations valid at arbitrary impurity content, but restricted to the weak-coupling isotropic limit. For the type-I/type-II/1 phase boundary, the differences between theory and experiment are attributed to anisotropy effects. On the type-II side of the phase diagram, theory predicts a significant dependence of the phase boundary on the impurity concentration, whereas the experiments fall on a rather uniform boundary curve.
Electron-Phonon Interaction of fcc and dhcp La under Pressure
Authors: Jarlborg Thomas , Sundqvist Bertil , Andersson Göran , Rapp Östen
Published: March 2014

The pressure dependence of the electron-phonon interaction of La has been studied for both phases by two methods: One is a calculation of λ and the other uses the calculated plasma frequency and the measured temperature and pressure dependence of the electrical resistivity. These results as well as a calculation of the spin-fluctuation contribution suggest that quenching of spin-fluctuations with pressure contribute to the increase of Tc with pressure in La.
Superconductivity of Phosphorus and Phosphorus-Arsenic Alloy under High Pressures
Authors: Shirotani Ichimin , Kawamura Haruki , Tsuburaya Kazuhiko , Tachikawa Kyoji
Published: March 2014

The pressure-induced superconductivity in phosphorus was measured along the five different paths. The effect of pressure on the superconducting transition temperature(Tc) strongly depends on the path in a P-T phase diagram. When red phosphorus was pressurized at 4.2 K, the Tc raised up to 13 K at 30 GPa. This is the highest temperature in elements. Phosphorus-arsenic alloy with composition P1-x Asx (x: 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6) was prepared at high temperatures and pressures. The superconductivity and phase transition in the alloy have been studied. The Tc of the alloy was lower than that of black Phosphorus. The superconductivity in P1-x Asx is closely related to the pressure-induced phase transition.
Normal State Resistivity of Aged Nb-65 at% Ti Alloy
Authors: Sastry V. Sankara , Kalavathi S. , Radhakrishnan T. S.
Published: March 2014

In this paper we report the normal state electrical resistance measurements on the superconductor Nb–65at% Ti alloy β quenched to room temperature and aged at 400°C for varying periods. We examine the low temperature data for a power law behaviour and find that the best fit of the data yields an exponent close to 1 irrespective of the aging time.
Effect of Crystal Dislocation on Superconductivity of Aluminum
Authors: Hiki Yosio , Kogure Yoshiaki , Itoh Arata
Published: March 2014

The ultrasonic attenuation was measured in high-purity aluminum single crystals containing dislocations. The measurements were made at room temperature, at a normal-conducting temperature (1.2 K), and in the superconducting state (0.4 - 1.18 K). From the normal-state data, the scattering cross-width of a dislocation for an electron was determined as 5.1×10-8 cm. The energy gap from the superconducting state data showed strong dependence on the density of dislocations, while the transition temperature was insensitive to the dislocations. The energy gap change was assumed to be originated from an elastic anisotropy induced by the internal stresses due to dislocations.
The Instability of High Tc States in Nb3Ge
Authors: Yasuda Takashi , Ono Fumiyoshi , Cheng Min Lin , Kusaba Mari , Fukami Takeshi , Mase Shoichi
Published: March 2014

Most of high Tc A–15 type Nb3Ge samples (Tc=23∼24 K) synthesized by us using CVD method contained a large quantity of the tetragonal Nb5Ge3 phase. These high Tc samples were unstable against thermal cycles and Tc's decreased down to ∼20 K. The coexisting Nb5Ge3 phase must play important roles to keep the high Tc state of Nb3Ge phase by stabilizing the A–15 type crystal structure and also to raise the magnetic flux pinning force density as pinning centers. It is suggested that the appearance of an anharmonic type potential acting on Nb atoms is closely related with high Tc of Nb3Ge phase.
Superconducting Transition Temperature of Single Crystal Nb3Ge
Authors: Matsumoto Yasukuni , Trapp G. , Heiden C.
Published: March 2014

The electrical resistance of single crystal Nb3Ge was measured by using precise micromanipulating equipment. Samples were prepared on the sapphire substrate by the CVD method. The largest grain size of the sample was more than 10 µm and the growth direction of these crystals (100). The superconducting transitions were measured when the distance between two potential probes was changed from less than 10 µm to more than 2 mm. If this distance was 2.3 mm, the transition curve consisted of several structures. When we measured the superconducting transition of one crystal, its shape was very sharp and the transition width was less than 0.2 K. The shorter the distance between two potential microprobes, the narrower the superconducting transition width.
High Resolution Electron Microscope Observations of Super- and Normal-States of A15 Superconductors
Authors: Yoshida Hiroyuki , Hashimoto Hatsujiro , Yokota Yasuhiro , Iwatsuki Masashi
Published: March 2014

Multi-beam Imaging of high resolution electron microscopy has been applied to observations of microstructure of Nb3Sn, Nb3Al and Nb3(Al, Ge) superconductors using JEM-2000EX and 2000SCEM at room temperature and 4 K, respectively. Atomic resolution images of the 001 oriented crystal show the similar image pattern with the 001 projection of the A15 structure and the Nb–Nb chains along the 001 direction appear as bright dots in the structure images. Planar defects and strain domains observed at room temperature suggest a role as pinning centres, similar to grain boundaries, for preventing flux movement. At 4 K the bright and dark contrast with 0.5-lnm was observed, when the crystal is in Bragg reflecting condition. The bright and dark contrast along the grain boundary parallel to the incident beam was also observed. Such the contrast anomaly may arise from the fluxoids distributing in the superconducting-state.
Origin of High Upper-Critical-Field in the Superconducting La-Chalcogenides
Authors: Ikeda Kôki
Published: March 2014

The “La3X4” (X=S or Se) compound, which undergoes a bcc-to-tetragonal distortion below room temperature, is a strong superconductor. The measurements of the electrical resistivity, the low temperature heat capacity, the ordinary Hall coefficient and the elasticity suggest that the superconducting transition temperature is governed by the density of states at the Fermi surface, whereas the high value of upper-critical-field in the cubic compound originates in an anomalously small mobility in the normal-state electron conduction and it is probably connected with the pre-martensitic transformation
Dual Conduction Characteristics Observed in Highly Resistive NbN Granular Thin Films
Authors: Yoshikawa Nobuyuki , Akeyoshi Tomoyuki , Kojima Manabu , Sugahara Masanori
Published: March 2014

We observed in highly resistive NbN thin films at low temperature dual conduction characteristics in clearly separated two region of their sheet resistance. In the specimens with R□Rc, however, the conduction characteristics can be explained supposing the KT effect for charge-soliton pairs.
Production of a Long Superconducting NbN Wire by the Sputtering Method
Authors: Morita Hiroaki , Watanabe Kazuo , Noto Koshichi , Fujimori Hiroyasu
Published: March 2014

An attempt has been made to produce a long wire of superconducting NbN compound by a reactive sputtering technique using a cylindrical pure Nb target. Among various metal- and alloy-wire substrate materials examined, a tungsten wire showed the best properties. Jc of the specimen deposited on the W wire was improved by annealing at temperatures up to 1200K, and the best properties are Tc of 15.7K, Jc of 1.84×105A/cm2 at 10T and 1.15×103A/cm2 at 20T.
Isotope Effect of NbHx and NbDx Films by the Reactive Sputtering Method
Authors: Mori Katsunori , Kasai Kiichiro , Isikawa Yosikazu , Sato Kiyoo , Ashida Kan , Watanabe Kuniaki
Published: March 2014

The variation of the superconducting transition temperature, Tc in NbHx and NbDx films, which were prepared by a method of hydrogen (deuterium) - reactive sputtering at room temperature, was investigated. The effect of hydrogen or deuterium absorption reduced Tc and a pronounced normal isotope effect was observed.
New Superconducting Phases in the Y–Os–Si System
Authors: Schellenberg L. , Braun H. F. , Segre C. U. , Gueramian M. , Muller J.
Published: March 2014

The existence of six new ternary phases has been established in the silicon-rich part of the Y–Os–Si system. At least two of these phases are superconducting with critical temperatures of 10.5 K and 9.7 K which are the highest transition temperatures observed for ternary silicides. The crystal structure of these phases appears to be closely related to the Lu5Co4Si14-type structure. Structure drawings of two of the phases with new structure types are included.
Superconductivity of the RE–Ir (RE: Y, Lu) Alloy Systems
Authors: Takano Yoshiki , Inaba Takamichi , Sekizawa Kazuko
Published: March 2014

Superconductivity of the rare earth-iridium (rare earth=RE: Y, Lu) alloy systems is investigated. In these systems, although pure Ir and the stoichiometric C15 Laves compounds (REIr2) are not superconducting above 1.3 K, the Ir-rich alloys become superconducting above 1.3 K. In the Y-Ir system, the occurrence of superconductivity with the transition temperature of about 3.5 K is due to the formation of the PuNi3-type phase. In the Lu-Ir system, the increase of the superconducting transition temperature is ascribed to the off-stoichiometry of the C15 Laves phase, which has a certain homogeneity range. In the C15 Laves phase, the electronic specific heat coefficient increases with increasing Ir concentration and this results in the increase of the superconducting transition temperature.
Stability of Rotating Couette Flow of Superfluid 4He: Analysis Based on Bekarevich-Khalatnikov's Hydrodynamics
Authors: Kashiwamura Shohei , Miyake Kazumasa , Yamada Kazuo , Yamauchi Jun
Published: March 2014

Stability of the rotating Couette flow in HeII is investigated on the basis of Bekarevich-Khalatnikov's hydrodynamics which includes both the effects of mutual friction (B and B') and of the vortex tension. It is shown that the stability sustained by the mutual friction B is easily decreased when the temperature is decreased through the lambda point say by 0.4K, while the vortex tension increases the stability sustained by the mutual friction B. These results suggest that the boundary friction on the vortex motion as well as the eddy viscosity due to the vortex motion are crucial to account for the stability which has been observed by Wolf et al.
EXAFS in NbSx (x≃3)
Authors: Iwazumi Toshiaki , Izumi Mitsuru , Oyanagi Hiroyuki , Yoshizaki Ryozo , Matsuura Etsuyuki
Published: March 2014

The EXAFS spectra were measured on the Nb K-shell absorption in semiconducting NbS3 and metallic NbSx (x≃3). The radial distribution function of semiconductor NbS3 shows that each metal atom forms Nb–Nb pair, which is identical to the previous results or X-ray structural analysis. The remarkable feature of the radial distribution function of metallic NbSx is the appearance of the prominent Nb–Nb peak around 3.0 Å, whose position is just in the middle of two Nb–Nb distances in semiconductor NbS3. It clearly shows that in the metallic crystal the Nb–Nb pair is deformed and the one-dimensional Nb chain is undistorted as the bulk-structural property.
Anisotropic Superconducting Transition of TaSe3
Authors: Morita Mitsuru , Yamaya Kazuhlko
Published: March 2014

It was found from measurements of anisotropic resistivity of TaSe3 by using the Montgomery method that TaSe3 showed an anisotropic superconducting transition. The usual superconducting transition was observed in the parallel direction to the b-axis, while in the perpendicular direction, a finite resistivity was observed even at the lowest temperature. The superconductivity of TaSe3 is found not to be bulk but of a filamentary nature.
Readout Characteristics of Micro-optical Head Operated in Bi-stable Mode
Authors: Ukita Hiroo , Katagiri Yoshitada , Uenishi Yuji
Published: March 2014

A micro-head consisting of a semiconductor laser and an external recording medium is proposed and its readout characteristics are investigated both experimentally and theoretically.
A newly developed optical head structure, a signal detection mechanism, media compatibility, signal-to-noise ratio improvement by an anti-reflection coated laser and dynamic data signal detection using a flying slider and a glass substrate disk are demonstrated.
A Multi-functional Reflection Type Grating Lens for the CD Optical Head
Authors: Tatsumi Kenji , Matsushita Tadashi , Ito Syo
Published: March 2014

A reflection type grating lens (RGL)which has four functions has been developed for the CD optical head ; a beam splitting, focusing and tracking error detection, and reflection. An optical head was constructed with the RGL. The experimental results show that the RGL has theoretical performance and CD signal reconstruction was performed with the jitter of 22ns.
Scattering and Induced Current Characteristics of a Beam Wave from Pits on Optical Disk using Boundary Element Method
Authors: Manabe Katsuya , Miyazaki Yasumitsu , Tanaka Takaaki
Published: March 2014

Numerical calculation of the pit scattering using boundary element method is described. The boundary element method can be applied to scattering of electromagnetic wave from various pit forms under different conditions of the incident wave. Scattered fields and induced currents due to the two-dimensional concave pit and the convex pit are calculated as functions of the depth (height) or width of pit, defocusing length, tracking error, track pitch and incident angle of the beam.
Compositional and Thickness Dependences of Thermo-magnetic Properties for TbCo Films
Authors: Ichihara Katsutarou , Shimanuki Senji , Yasuda Nobuaki
Published: March 2014

For a better understanding of the dynamic characteristics of TbCo magneto-optical disks, the thermo-magnetic properties of TbCo films with various compositions and thicknesses were investigated. The measured Ms dependence on film temperature suggested that the effect of the leakage field in the write/erase process for TbCo films would be larger than that for Fe-based films. And the spacial Ms profile of the heated spot for a thinner TbCo film was more steeper than that for a thicker film. The domain nucleation process and the wall stiffness were estimated from statically obtained thermo-magnetic properties. Qualitative relationship among dynamic characteristics, such as optimum recording power and jitter, were clearly obtained.
Direct Overwrite by Light Power Modulation on Magneto-Optical Multi-Layered Media
Authors: Saito Jun , Sato Masatoshi , Matsumoto Hiroyuki , Akasaka Hideki
Published: March 2014

The present authors have developed a new direct overwrite method on multi-layered Magneto-optical(MO) memory media by light power modulation [1]. (In this experiment double-layered MO memory media are used.) The key points were the media constituing of a memory layer and a reference layer, and an auxiliary magnet which initializes the reference layer. The materials of the two thin film layers we have tested were TbFe/TbFeCo and TbFe/GdTbFe. The both combinations worked well. The former conbination gave us the following result; media velocity = 13.4m/sec, readoput C/N (RBW = 30kHz) = 54dB, 47dB, 44dB for 1MHz, 6MHz, 8MHz respectively.
High Performance Optical Disk Storage System
Authors: Itao Kiyoshi , Hara Shigeji
Published: March 2014

Requirements for optical disk memories in data storage systems and present engineering limits related to optical disk technologies are discussed. Advanced technologies that compensate the gap between the requirements and the limits, such as high performance phase change media, an integrated optical head and so on, are investigated, following a description of the trends in performance of optical disk storage systems.
A Floating-Lens Actuator
Authors: Rosmalen G. E. van
Published: March 2014

An actuator for optical recorder applications is described in which the objective lens is electromagnetically suspended in a configuration of magnetic coils, free from mechanical contact. The coil configuration is such that the lens can be driven in five degrees of freedom. An optical strategy has been devised to generate the necessary error signals for servo control.
An Evaluation of the Reproducing Methods on Optical Digital Disk
Authors: Furukawa Teruo , Nakane Kazuhiko , Tanaka Kunimaro , Nakada Masanori
Published: March 2014

Evaluation method for the reproduction system of optical digital disk has been developed. For differentiated and differential detection methods, either of which are typical reproduction system to (2-7)RLL-RZ recording, the relationship between recording density and bit error rate was estimated taking signal to noise ratio and recording pit shape into consideration.
Artificial Intelligence as applied to Optical Image Filing
Authors: Fujisawa Hiromichi
Published: March 2014

This paper presents an image of a futuristic document filing system, or an advanced filing system, based on an analysis of the filing activity. Then, the techniques in artificial intelligence required to realize this system are discussed. The approaches proposed here are document understanding and knowledge-based filing. The document understanding technology may automate document image analysis and information extraction using character recognition. A method of image segmentation using layout knowledge is described. Knowledge-based filing, on the other hand, can ease the user to register and retrieve documents with the help of inference applied to domain specific knowledge. Software simulations and experiments on a prototype system are also described.
Analog Video Recording on Magneto-Optical Disk
Authors: Tanaka Fujio , Tani Yukio , Suzuki Shizuo , Nakagawa Shozo
Published: March 2014

Color moving pitures were recorded on the magneto-optical disk by a frequency modulation method. Two types of FM modems whose bandwidths were 6 MHz and 9.3 MHz were developed. In the latter modem, the quality of reproduced pictures was as good as that of the Video Disc. It was confirmed that the horizontal resolution through the ITE test patterns was over 400 lines and the signal-to-noise ratio measured by video noise meter was 40 dB or more.
Analog Video Signal Recording and Playback Characteristics of Magneto-optical Memory Disk
Authors: Kashihara Toshiaki , Kobukata Mieko , Momoo Kazuo , Sugano Takafumi , Okino Yoshihiro
Published: March 2014

For real time recording of analog video signals, we developed a high performance RE-TM magneto-optical disk by the technique of alloy target sputtering and a new optical pickup based on the principle of Brewster angle. Real time recording of analog video signals with SNR of 45 dB and estimated life time of more than 10 yerars was achieved.
Optical Head Controlled by Double Diffraction Patterns
Authors: Nakano Takayuki , Suzuki Seizoh , Honma Kazutaka , Kinoshita Mitsuo , Sasaki Isamu
Published: March 2014

An optical head with 10 mm in height and 10 g in weight for practical use of optical mass storage systems, applied a thin lens-actuator, has been successfully developed by employing double diffraction patterns for focusing and tracking error detection. The first diffraction pattern for the focusing error detection is derived from a particular detecting lens, and by a so-called push-pull method the second for the tracking error detection is also used. The lens for the focusing error detection consists of some decentered surfaces and also has a short detecting distance. An objective lens is supported by four thin springs. Therefore the height of this lens-actuator becomes less than 10 mm. The thin optical head and a method for the focusing error detection of the optical head with a single-beam optical system are described.
Magneto-Optical Disc with Casting Substrate
Authors: Kudoh Y. , Maruno Y. , Ieki M. , Kawabata H. , Yamamoto K.
Published: March 2014

As a grooved substrate for magneto-optical disc, we have developed a vinylester casting substrate: this substrate features excellent optical characteristics, high resistance to heat, dust-free performance, high resistance to chemicals and good moldability. For curing acceleration of resin, microwave heating is employed, thereby reducing the molding time to 15 minutes or less. As a comparison result of recording/readout characteristics for vinylester substrate disc with those for glass substrate disc, high characteristics have been obtained; equivalent characteristics or higher, that is, C/N = 54dB (domain length: 0.9µm), BER ∼ 10-5.
New Write-once Optical Media Using Azulenium Dye
Authors: Miyazaki Takeshi , Fukui Tetsuro , Takano Katsuhiko , Oguchi Yoshihiro , Santoh Tsuyoshi , Nishide Katsuhiko , Takasu Yoshio
Published: March 2014

New write-once optical media comprising the azulenium dye film are reported. Azulenium dyes having strong absorbance in the near infrared range are synthesized and studied about their optical and thermal properties. The dye film made by a spin-coating process, has a sufficient absorbance and reflectance at a wave length of 830nm. The new media, comprising the dye film have high recording sensitivity and a sharp threshold in recording characteristics.
Amorphous Silicon Film: A New Erasable Medium for Optical Recording
Authors: Lee M. C. , Huang C. R. , Lin C. C.
Published: March 2014

Recently we demonstrated that the laser annealed silicon film could be amorphized by 800 picoseconds laser pulse as checked by the greatly reduced Raman intensity. Associated with this phase change is a sharp contrast in optical reflection that indicates an alternative to erasable medium.
Crystallization of Amorphous Marks in SbTe Erasable Optical Storage Media
Authors: Yagi Shogo , Fujimori Susumu , Yamazaki Hiroki
Published: March 2014

We present new measuring methods for amorphizing sensitivity, erasing time and amorphous life at room temperature of small amorphous marks formed by laser quenching. It is found that the Sb2Te3 film has both the shortest erasing time and the longest life of the SbxTe1-x sputtered films. In addition, the amorphous state of marks crystallizes at a lower temperature than that of as-sputtered films.
Observation of Fast Microscopic Phase Change Phenomena of Chalcogenide Thin Films
Authors: Ueno Fumiaki
Published: March 2014

Fast microscopic phase change phenomena are observed in real time by measuring reflectivity and transmissivity of chalcogenide thin films. The method for calculating the complex index of refraction from reflectivity and transmissivity in microscopic area is also developed. By comparing the calculated reflectivity and transmissivity with the measured ones, the dynamic phase change phenomena of the film during and after the irradiation can be guessed. Phase change of TeOx film, Te-Ge-Sn-Au film and GeTe film is observed. For the TeOx film, a model for crystallizing process is proposed.
High Speed Overwritable Phase Change Optical Disk Material
Authors: Yamada Noboru , Ohno Eiji , Akahira Nobuo , Nishiuchi Ken'ichi , Nagata Ken'ichi , Takao Masatoshi
Published: March 2014

It was found that GeTe-Sb2Te3 pseud-binary amorphous alloy films showed remarkably fast switching properties to laser irradiation. By the static laser irradiation test, the film whose composition corresponded to stoichiometric compound of GeSb2Te4 were crystallized within 50ns of pulse duration at power of 8mW, whilst they could be amorphized with the same pulse duration at power of 20mW. Direct overwriting cycle test was performed on the revolving disk system for 105 times using single laser beam. CNR of more than 50dB and erasability of -22dB were obtained for linear velocity of 22m/s and overwriting frequencies of 5 and 7 MHz. The laser powers were 22 mW for recording and 10 mW for erasing. These materials will be applicable to high data rate direct overwritable disk media.
A Method for Evaluating Birefringence in Plastic Substrates of Magneto-optical Disks
Authors: Fukunishi Shuzo , Hatakeyama Iwao
Published: March 2014

A simple method for evaluating birefringence in plastic substrates for magneto-optical disks is proposed. Various kinds of substrates are characterized by this method and the results are discussed in connection with magneto-optical properties.
New Data on GLP-1s, Diabetic Retinopathy, and CGMs—Highlights From the ADA’s Scientific Sessions
Authors: Abbasi Jennifer
Published: July 2024

This Medical News article is an interview with Robert Gabbay, MD, PhD, the American Diabetes Association’s chief scientific and medical officer.
Missing carcasses, lost nutrients: Quantifying nutrient losses from deer culling practices in Scotland
Authors: Ferraro Kristy M. , Hirst Christopher
Published: July 2024

Deer management has become an integral part of ecosystem recovery efforts across the globe. Within Scotland, annual deer culls have been implemented to control deer browsing, with the carcasses most often removed from the landscape. Given that animal bodies concentrate large quantities of nutrients, this practice may deplete ecosystems of vital nutrients.

We quantified the nitrogen, phosphorous and calcium losses from the removal of culled deer carcasses using nationwide statutory cull reports for four deer species in Scotland between 2010 and 2021. We estimate that annual losses from carcass removal over this period averaged 195,652 kg of nitrogen, 152,834 kg of phosphorus and 251,188 kg of calcium across Scotland. While both red and roe deer were culled at a much higher rate than the other two species red deer culls accounted for approximately 70% of the nutrients lost. Further, while large quantities of all three nutrients were removed from the landscape, calcium losses were particularly high.

We then calculated nutrient losses within the three land classifications used in statutory cull reporting—agricultural areas, open range and woodlands—across Scotland's Deer Count Areas. Using data from the literature, we considered these losses in the context of other major environmental inputs and outputs within each land classification. Our results demonstrate that while open range lost more nutrients compared to the other two land classifications, culling resulted in high rates of phosphorus and calcium loss throughout all land classifications when compared to other environmental inputs.

Practical implication. Our findings suggest that current practices of carcass removal are gradually stripping nutrients from the Scottish landscape, potentially undermining habitat recovery goals. While this study offers a preliminary, coarse scale summary of the issue, the way forward requires further study of local effects from carcass removal on nutrient pools and balancing deer management with habitat function through interwoven deer and nutrient management strategies.
Letter to the editor
Authors: Ventrell Marvin
Published: July 2024

I read this week's featured article, “Shatterproof, McLellan Want Treatment Focused on Results” (see https://onlinelibrary.wiley.com/doi/10.1002/adaw.34186) with considerable interest. Dr. McLellan could not be more correct that our field must focus on results, and it was good to see Shatterproof's ATLAS program mentioned. It was disappointing, however, that other outcomes tracking work in our field were omitted, most notably, the pioneering work of the Foundation for Recovery Science and Education (FoRSE). Both efforts are important, complementary, collaborative, but if taken in isolation do not produce an adequate picture of the considerable treatment outcomes (results) work being conducted in the field.
The Second Laser Revolution in Chemistry: Emerging Laser Technologies for Precise Fabrication of Multifunctional Nanomaterials and Nanostructures
Authors: Manshina Alina A. , Tumkin Ilya I. , Khairullina Evgeniia M. , Mizoshiri Mizue , Ostendorf Andreas , Kulinich Sergei A. , Makarov Sergey , Kuchmizhak Aleksandr A. , Gurevich Evgeny L.
Published: July 2024

The use of photons to directly or indirectly drive chemical reactions has revolutionized the field of nanomaterial synthesis resulting in appearance of new sustainable laser chemistry methods for manufacturing of micro‐ and nanostructures. The incident laser radiation triggers a complex interplay between the chemical and physical processes at the interface between the solid surface and the liquid or gas environment. In such a multi‐parameter system, the precise control over the resulting nanostructures is not possible without deep understanding of both environment‐affected chemical and physical processes. The present review intends to provide detailed systematization of these processes surveying both well‐established and emerging laser technologies for production of advanced nanostructures and nanomaterials. Both gases and liquids are considered as potential reacting environments affecting the fabrication process, while subtractive and additive manufacturing methods are analyzed. Finally, the prospects and emerging applications of such technologies are discussed.
Correlations of Socioeconomic and Clinical Determinants with United States County‐Level Stroke Prevalence
Authors: Stulberg Eric L. , Lisabeth Lynda , Schneider Andrea L. C. , Skolarus Lesli , Kershaw Kiarri N. , Zheutlin Alexander R. , Harris Benjamin R. E. , Sarpong Daniel , Wong Ka‐Ho , Sheth Kevin N. , de Havenon Adam
Published: July 2024

Socioeconomic status (SES) is a multi‐faceted theoretical construct associated with stroke risk and outcomes. Knowing which SES measures best correlate with population stroke metrics would improve its accounting in observational research and inform interventions. Using the Centers for Disease Control and Prevention's (CDC) Population Level Analysis and Community Estimates (PLACES) and other publicly available databases, we conducted an ecological study comparing correlations of different United States county‐level SES, health care access and clinical risk factor measures with age‐adjusted stroke prevalence. The prevalence of adults living below 150% of the federal poverty level most strongly correlated with stroke prevalence compared to other SES and non‐SES measures (correlation coefficient = 0.908, R2 = 0.825; adjusted partial correlation coefficient: 0.589, R2 = 0.347). ANN NEUROL 2024;96:739–744