bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct imaging of spin‐reorientation transitions in ultrathin Ni films by spin‐polarized low‐energy electron microscopy
Authors: Klein C. , Ramchal R. , Farle M. , Schmid A. K. 
Published: November 2006

AbstractThe thickness‐dependent spin‐reorientation transition (SRT) in ultrathin Ni films grown on a stepped Cu(100) substrate was studied by spin‐polarized low‐energy electron microscopy (SPLEEM). Magnetic contrast in SPLEEM is proportional to the scalar product of beam polarization and magnetization of the film. This dependence was exploited to determine the local 3D magnetization vector by evaluating magnetic contrast in images obtained using three orthogonal polarizations of the incident electron beam. Using this method, we were able to directly image the rotation of the magnetization vector in Ni films from in‐plane and parallel to the steps to out‐of‐plane and perpendicular to the steps of the substrate. We found the SRT to proceed via two mechanisms: continuous growth of the out‐of‐plane component, accompanied by discontinuous reorientation of the in‐plane component via domain nucleation. Copyright © 2006 John Wiley & Sons, Ltd.
Light emission by surface plasmons on nanostructures of metal surfaces induced by high‐energy electron beams
Authors: Yamamoto N. , Nakano M. , Suzuki T. 
Published: November 2006

AbstractLight emission by surface plasmons induced by high‐energy electron beams was investigated for several nanostructures, i.e. two touching particles of silver, a silver whisker and stripes on a flat metal surface. The emission spectra showed that the resonant peaks originated from the resonant modes of surface plasmons. Monochromatic photon maps taken at peak wavelengths clearly revealed the spatial distribution of surface plasmons on the metal nanostructures. Copyright © 2006 John Wiley & Sons, Ltd.
A novel approach to derive absorption coefficient of secondary electrons as applied to Ti and TiO2
Authors: Iyasu Takeshi , Inoue M. , Yoshikawa H. , Shimizu Ryuichi 
Published: November 2006

AbstractA novel approach is proposed to derive a theoretical curve, δ(EP), from the equation

for construction of a database of the secondary electron emission (k, α), where δ(EP) and [dE/dz] are the secondary yield and energy dissipation in depth, respectively, for incident electrons of primary energy, EP. α is the absorption coefficient of the secondary electron and k the secondary emission coefficient of the specimen. This approach is based on the use of the theoretical energy dissipation in depth [dE/dz], which is to be obtained from Monte Carlo calculation, and the experimental δex(EP) or a set of δm and Em to be measured in experiment, where δm is the maximum secondary yield obtained at primary electron energy Em. Comparing the theoretical δ(EP) with the experimental δex(Ep) or a set of δm and Em one can obtain the best‐fit value of α and, then, k.Since data‐sets of δm and Em have been reported for a wide variety of materials so far, the proposed approach enables us to derive the α and k values for the materials of practical interest, filling up the deficiency of reliable data on the secondary emission.This approach was verified by applying it to Be, Ag, Pt and Bi, of which δm and Em have been published, leading to the confirmation that α‐values derived by the present approach agree very well with the experimental ones. Experiments was also performed to measure δ(EP) for Ti and TiO2 to obtain α and k‐values. The results are α−1≅0.5 nm and k≅0.046, for Ti, α−1≅0.7 nm and k≅0.028 for TiO2. Copyright © 2006 John Wiley & Sons, Ltd.
Characteristics of a cluster‐ion beam of Os3(CO)n+ (n = 7 or 8) for low‐damage sputtering
Authors: Fujiwara Yukio , Kondou Kouji , Teranishi Yoshikazu , Nonaka Hidehiko , Fujimoto Toshiyuki , Kurokawa Akira , Ichimura Shingo , Tomita Mitsuhiro 
Published: November 2006

AbstractA cluster‐ion source has been developed to produce stable ion beams of metal‐cluster‐complex ions. As a metal cluster complex, triosmium dodecacarbonyl, Os3(CO)12, was used, which has a molecular weight of 906.7. Using the ion source, energy dependence of beam current and sputtering yield of silicon bombarded with Os3(CO)n+ (n = 7–8) were investigated at beam energies from 2 to 10 keV under the normal incidence condition. By high‐resolution Rutherford backscattering spectrometry (HR‐RBS), a silicon target bombarded with the normally incident Os3(CO)7–8+ ions at 10 keV with oxygen flooding at 5 × 10−4 Pa was analyzed. The experimental results showed that the ion‐beam current increased almost linearly with the acceleration voltage. It was found that the sputtering yields of silicon with Os3(CO)7–8+ ions varied substantially with beam energy. The sputtering yield with Os3(CO)7–8+ at 10 keV was higher than that with SF5+ or Ar+ by a factor of 3–20, whereas the yield at 3 keV was lower than that with Ar+. In the case of 2 keV, deposition was found to occur on the silicon surface. The substantial variation in the sputtering yield with beam energy would arise from the lower kinetic energy of each atom constituting the metal‐cluster‐complex ions. From HR‐RBS results, it was confirmed that the constituent atoms of the Os3(CO)7–8+ ions, Os, C, and O, were implanted into the silicon target. The observed depth profiles of Os and C atoms were in good agreement with results of TRIM simulation, while that of the O atom was significantly different from the simulation results. The depth profile of the O atom was examined in terms of oxygen diffusion and implantation. Copyright © 2006 John Wiley & Sons, Ltd.
Photoemission electron microscopy with chemical sensitivity: SPELEEM methods and applications
Authors: Locatelli A. , Aballe L. , Mentes T. O. , Kiskinova M. , Bauer E. 
Published: November 2006

AbstractThe instrumentation for synchrotron radiation X‐ray photoemission electron microscopy (XPEEM) has recently undergone significant improvements, finding application in diverse fields such as magnetism, chemistry, surface science and nanostructure characterization. The spectroscopic photoemission and low energy electron microscope (SPELEEM) operational at the ‘Nanospectroscopy beamline’ at the Elettra synchrotron facility combines structural and spectroscopic analysis methods in a single instrument, exploiting the inherent chemical sensitivity of X rays. The SPELEEM reaches an energy resolution of 0.2 eV and a lateral resolution of few tens of nanometers in XPEEM. Selected results are used to illustrate the spectro‐microscopic capabilities of the SPELEEM, and the usefulness of available complementary methods such as low energy electron microscopy (LEEM) and micro‐spot low energy electron diffraction (LEED). Copyright © 2006 John Wiley & Sons, Ltd.
Analysis of GOI‐MOSFET with high‐kgate dielectric and metal gate fabricated by Ge condensation technique
Authors: Park Mungi , Bea Jicheol , Fukushima Takafumi , Koyanagi Mitsumasa 
Published: November 2006

AbstractIn order to improve the complementary metal‐oxide‐semiconductor (CMOS) circuit performance under sub‐100 nm technology nodes with low supply voltages, a metal‐oxide‐semiconductor field‐effect transistor (MOSFET) including a high mobility channel and a silicon‐on‐insulator (SOI) structure is a promising device design. According to The International Technology Roadmap for Semiconductors (ITRS), a 25‐nm MOSFET with a gate oxide equivalent oxide thickness (EOT) of 5–8 nm will be produced by 2010. Several groups have reported thermally stable gate dielectrics such as HfO2, ZrO2, HfxSi1−xO, HfOxNy, ZrOxNy, and Ln2O3. However, considering the relatively thick interfacial layer (∼0.5 nm SiOx) and the relatively low dielectric constant (10–20) of these materials, it is very difficult to scale down the EOT below 1 nm. In this paper, we report on the electrical characteristics of sputtered HfO2with an EOT of 0.78 nm. We report Ge metal‐insulator‐semiconductor field‐effect transistors (MISFETs) with HfO2and W/W2N metal gate electrode on germanium‐on‐insulator (GOI) wafer obtained by the new graded Ge condensation method. Excellent device characteristics are achieved with a subthreshold swing of 80 mV/dec and low gate leakage. Copyright © 2006 John Wiley & Sons, Ltd.
Study on the origin of the anisotropic dielectric properties of the Au‐adsorbed Si(001) vicinal surface
Authors: Minoda Hiroki , Yamamoto Naoki 
Published: November 2006

AbstractA study on the origin of the anisotropic dielectric properties of Au‐adsorbed Si(001) vicinal surface was carried out by observation of the electron‐beam‐induced light emission from the Si(001) 5 × 3.2‐Au surface and the Au‐adsorbed Si(111) vicinal surface by using a light detection system combined with a transmission electron microscope. It was found that the polarization of the light emitted from steps of the Si(001)‐Au surface is different from that from the Si(001) 5 × 3.2‐Au surface, but is similar to that from the (119) facet in the case of the Au adsorbed Si(001) vicinal surface. The polarization depends on the numbers of steps, and the step bands that include a larger number of steps show higher polarization. The polarization of the emitted light from the Au‐adsorbed Si(111) vicinal surface is much weaker compared to that from the Au‐adsorbed Si(001) surface. These results suggest that the origin of the anisotropic dielectric properties of the Au‐adsorbed Si(001) vicinal surface is due to the anisotropy of the atomic structure of the surface. Copyright © 2006 John Wiley & Sons, Ltd.
Shave‐off depth profiling of dendritic short‐circuit growth caused by ion migration
Authors: Yamamoto T. , Maekawa A. , Ishizaki Y. , Tanaka R. , Owari M. , Nojima M. , Nihei Y. 
Published: November 2006

AbstractThe rapid progress made in recent years in the field of nanotechnology has been remarkable. In semiconductor devices, it has become increasingly important to evaluate the reliability of not only the device itself but also the connection between the circuit board and the device terminals. This is especially true for semiconductor device packages developed in response to the needs of high‐density mounting. Therefore, new problems of insulation degradation are anticipated during the advances of semiconductor device packaging. Ion migration is one of the problems. Although the classical model of ion migration has been well known for several decades, the details of the migration process in semiconductor device packages are still unknown. In this study, we have analyzed the dendritic short‐circuit growth of Cu caused by ion migration in semiconductor device packages using shave‐off depth profiling and TEM‐EDX. The highly sensitive and unique depth profiling has provided indispensable information for discussion on the mechanisms of the dendritic short‐circuit growth. Copyright © 2006 John Wiley & Sons, Ltd.
Improvement of a method for reconstructing the three‐dimensional atom probe (3DAP) data
Authors: Chiba T. , Nojima M. , Owari M. 
Published: November 2006

AbstractA method for reconstructing the three‐dimensional atom probe (3DAP) data with cluster ions, which are composed of the so‐called undetected atoms, has been developed. The position and structure of clusters composed of undetected atoms may be determined by taking into account the number of atoms within a sphere that centers at a grid‐point set in the reconstructed 3DAP data. On the basis of the simulation data, it was demonstrated that the position of each undetected atom constituting a cluster with nine or fewer atoms could be determined using the method proposed. Copyright © 2006 John Wiley & Sons, Ltd.
Highly sensitive ion imaging system using direct combination of a stacked‐type solid‐state imager and a microchannel plate driven by LabVIEW software
Authors: Sakamoto Naoya , Yurimoto Hisayoshi 
Published: November 2006

AbstractA direct ion imaging system with single ion detection and high‐precision imaging modes has been developed. This system is composed of a movable microchannel plate unit and a stacked CMOS‐type active pixel sensor (SCAPS). Capabilities of single ion detection were evaluated by ion irradiations using secondary ion mass spectrometry. The experiment shows that this system accurately detected single incident ions. Copyright © 2006 John Wiley & Sons, Ltd.
In situ scanning electron microscopy of single‐walled carbon nanotube growth
Authors: Takagi Daisuke , Homma Yoshikazu , Suzuki Satoru , Kobayashi Yoshihiro 
Published: November 2006

AbstractWe have developed an in situ observation technique for chemical vapor deposition (CVD) of single‐walled carbon nanotubes (SWNTs) using a scanning electron microscope (SEM). The growth of SWNTs in the SEM is achieved by employing low‐pressure ethanol vapor as the carbon source and cobalt as the catalyst. The time evolution of SWNT growth is successfully traced by alternate CVD growth in low vacuum and SEM observation in high vacuum. By limiting the nanotube growth areas, individual SWNT growth could be observed. Copyright © 2006 John Wiley & Sons, Ltd.
Stable multiwalled carbon nanotube electron emitter operating in low vacuum
Authors: Suga Hiroshi , Abe Hidekazu , Tanaka Miyuki , Shimizu Tetsuo , Ohno Teruaki , Nishioka Yasushiro , Tokumoto Hiroshi 
Published: November 2006

AbstractWe have investigated field emission (FE) properties of an individual multiwalled carbon nanotube (CNT) under low‐vacuum regions around 10−3 Pa. Current versus voltage characteristics of the present CNT emitters were found to be explicable on the basis of the Fowler–Nordheim (F–N) formalism. Time trace of the FE current exhibited more than 30% fluctuation about the mean value, and the lifetime was less than 5 h. Scanning electron microscopy (SEM) observation elucidated that the lengths of the CNTs were reduced after prolonged field emission, plausibly because of local heating induced by the large current density at the apex. To prolong the lifetime, we attempted a type of feedback system by inserting a high ohmic resistance between the electron emitter and the power supply. As a result, the current fluctuation decreased from ∼30% to 2% at 0.1 µA, and the lifetime increased from 5 to 50 h. Finally, an SEM was equipped with both the emitter systems, with and without resistance, which were designed for the CNT field emitter. The SEM images taken by using the emitter with resistance showed consistently brighter appearance, whereas those taken without the resistance exhibited fluctuations in the image brightness. Copyright © 2006 John Wiley & Sons, Ltd.
Sb on In/Si(111) processes with dynamically observable LEEM, selected area LEED and chemically analyzed SR‐XPEEM
Authors: Nakaguchi A. , Guo F.‐Z. , Hashimoto M. , Ueda M. , Yasue T. , Matsushita T. , Tamenori Y. , Kinoshita T. , Kobayashi K. , Koshikawa T. 
Published: November 2006

AbstractSb adsorption processes on In/Si(111) √3 × √3 and √31 × √31 surfaces were investigated in the present work. The dynamic growth behavior was observed with low energy electron microscopy (LEEM), and the local surface structure change was monitored with selected area low energy electron diffraction (LEED). X‐ray generated photo emission electron microscopy using synchrotron radiation (SR‐XPEEM) was employed in order to see the variation of the chemical state on the surface. On both √3 × √3 and √31 × √31 surfaces, Sb adsorption induces the surface structural change and modifies the chemical interaction of In atoms with Si. In atoms are replaced by impinged Sb atoms, and the discharged In atoms form islands. Copyright © 2006 John Wiley & Sons, Ltd.
Bayesian estimation of false‐negative rate in a clinical trial of sentinel node biopsy
Authors: Newcombe Robert G. 
Published: November 2006

AbstractEstimating the false‐negative rate is a major issue in evaluating sentinel node biopsy (SNB) for staging cancer. In a large multicentre trial of SNB for intra‐operative staging of clinically node‐negative breast cancer, two sources of information on the false‐negative rate are available.Direct information is available from a preliminary validation phase: all patients underwent SNB followed by axillary nodal clearance or sampling. Of 803 patients with successful sentinel node localization, 19 (2.4 per cent) were classed as false negatives.Indirect information is also available from the randomized phase. Ninety‐seven (25.4 per cent) of 382 control patients undergoing axillary clearance had positive axillae. In the experimental group, 94/366 (25.7 per cent) were apparently node positive. Taking a simple difference of these proportions gives a point estimate of −0.3 per cent for the proportion of patients who had positive axillae but were missed by SNB. This estimate is clearly inadmissible.In this situation, a Bayesian analysis yields interpretable point and interval estimates. We consider the single proportion estimate from the validation phase; the difference between independent proportions from the randomized phase, both unconstrained and constrained to non‐negativity; and combined information from the two parts of the study. As well as tail‐based and highest posterior density interval estimates, we examine three obvious point estimates, the posterior mean, median and mode. Posterior means and medians are similar for the validation and randomized phases separately and combined, all between 2 and 3 per cent, indicating similarity rather than conflict between the two data sources. Copyright © 2006 John Wiley & Sons, Ltd.
Multilayered Si/Ni Nanosprings and Their Magnetic Properties
Authors: He Yuping , Fu Junxue , Zhang Yang , Zhao Yiping , Zhang Lijiao , Xia Ailin , Cai Jianwang 
Published: November 2006

AbstractA two‐turn, eight‐armed, rectangular Si/Ni heterogeneous nanospring structure on Si(100) has been fabricated using a multilayer glancing‐angle deposition technique. The multilayered nanosprings with a height of ≈1.98 μm were composed of alternating layers of amorphous Si nanorods ≈580 nm in length and face‐centered cubic Ni nanorods ≈420 nm in length, both with a diameter of ≈35 nm. The magnetic anisotropy of the nanosprings showed that the in‐plane easy and hard axes were parallel and perpendicular to the Ni nanorod plane, respectively. The out‐of‐plane magnetic hysteresis loop was very sensitive to the applied magnetic field direction when rotating the nanosprings about their in‐plane hard axis, and the magnetization measurement revealed that the nanosprings tilted at ≈7.5° toward the plane of the Si nanorods. The magnetic anisotropy of the nanosprings is determined by their structure, and the experimental results can be interpreted by the shape anisotropy energy.
Ageing in yeast does not enhance prion generation
Authors: Shewmaker Frank , Wickner Reed B. 
Published: November 2006

AbstractThe yeast prions [URE3] and [PSI+] are self‐propagating amyloids of Ure2p and Sup35p, respectively. The analogous transmissible spongiform encephalopathies of mammals and other amyloidoses are largely diseases of later life. From normal strains lacking the prions, we isolated old cells and measured the frequency of de novo [URE3] and [PSI+] prion generation. We find no evidence that ageing of yeast increases the frequency of prion occurrence. Copyright © 2006 John Wiley & Sons, Ltd.
Substrate‐inducible versions of internal alternative NADH : ubiquinone oxidoreductase from Yarrowia lipolytica
Authors: Garofano Aurelio , Eschemann Andrea , Brandt Ulrich , Kerscher Stefan 
Published: November 2006

AbstractIn standard laboratory strains of the obligate aerobic yeast Yarrowia lipolytica, respiratory chain complex I (proton‐translocating NADH : ubiquinone oxidoreductase) is an essential enzyme, since alternative NADH dehydrogenase activity is located exclusively at the external face of the mitochondrial inner membrane. Deletions and other loss‐of‐function mutations in genes for nuclear coded subunits of complex I can be obtained only when an internal version of the latter enzyme, termed NDH2i, is introduced. In contrast to recent findings with Neurospora crassa, external alternative NADH dehydrogenase activity is dispensable in complex I deletion strains of Y. lipolytica. We used regulable promoters to create strains which express internal alternative NADH dehydrogenase in a substrate‐dependent manner. The ability to switch between complex I‐dependent and ‐independent mode of growth simply by changing the carbon source is an important prerequisite for screens for both loss‐of‐function and inhibitor resistance mutation. The isocitrate lyase promoter (pICL1), in combination with a NDH2i allele that results in reduced expression and activity, was most promising. In the presence of complex I inhibitors, this construct allowed growth on acetate, but not on glucose minimal media. A somewhat higher background was observed with the acyl‐CoA oxidase 2 (pPOX2) promoter on glucose minimal media. Copyright © 2006 John Wiley & Sons, Ltd.
In vitro characterization of the Mig1 repressor from Saccharomyces cerevisiae reveals evidence for monomeric and higher molecular weight forms
Authors: Needham Patrick G. , Trumbly Robert J. 
Published: November 2006

AbstractThe Mig1 DNA‐binding protein of Saccharomyces cerevisiae was expressed and purified from yeast and the physical properties were characterized by several methods, including gel filtration, sucrose gradient sedimentation and native gel electrophoresis. Purified Mig1 exists as a monomer with a Stokes' radius of 48 Å and a sedimentation coefficient of 3.55 S. Mig1 has an elongated shape with a frictional coefficient of 1.83. The Kd of purified Mig1 for the SUC2 A site is 2.8 nM and for SUC2 B site 25.8 nM; these values were similar for Mig1 purified from repressed and derepressed cells. Full‐length Mig1 expressed in yeast binds more tightly to SUC2 B than bacterially expressed GST–Mig1. Sucrose gradient sedimentation resolved a larger molecular weight form of Mig1 in whole‐cell extracts that was not seen in purified samples and may represent a complex with another protein. This complex is found within the nucleus and is seen only in repressed cells. Mig1 exists in multiple phosphorylation states and only less phosphorylated forms of Mig1 are associated with this complex. Copyright © 2006 John Wiley & Sons, Ltd.
Glyceryl ether, wax ester and triglyceride composition of the mouse preputial gland
Authors: Sansone Gail , Hamilton James G. 
Published: November 2006

AbstractMajor lipid classes of the preputial gland of the mouse have been identified as wax ester, neutral plasmalogen, glyceryl ether diester and triglyceride. The chain lengths and degree of unsaturation in the aliphatic moieties of the alk‐1‐enyl and alkyl glyceryl ethers are similar to those of the fatty alcohols of the wax ester fraction. This lends support to the theory that long chain fatty alcohols can be direct precursors of the aliphatic chains of glyceryl ethers. The striking qualitative, as well as quantitative, similarities between the alkyl and alk‐1‐enyl moieties of the glyceryl ethers in the neutral lipid fraction suggest that they share a common pathway of biosynthesis or are interconvertible. Neutral plasmalogens and glyceryl ether diesters contain significant amounts of odd‐numbered and branched fatty acids, unlike the fatty acids of the triglycerides; therefore, the biosynthesis of neutral plasmalogens and glyceryl ether diesters may not be related to the biosynthesis of triglycerides.
Lecithin‐protein interaction in the GTP‐dependent acyl‐CoA synthase
Authors: Galzigna Lauro , Sartorelli Lodovico , Rossi Carlo R. , Gibson David M. 
Published: November 2006

AbstractThe enzymic activity of the GTP‐dependent acyl‐CoA synthase isolated from rat liver mitochondria is affected by removal and addition of lecithin (3). Purified preparations of this enzyme contain bound lecithin. In this presentation the nature of the lecithin‐protein interaction is examined. From binding measurements at different temperatures it is possible to postulate which type of secondary valence bonds is holding the protein and lecithin together.