bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving the Near-Field Transmission Efficiency of Nano-Optical Transducers by Tailoring the Near-Field Sample
Authors: Sendur Kursat , Challener William 
Published: August 2010

AbstractDespite research efforts to find a better nano-optical transducer for light localization and high transmission efficiency for existing and emerging plasmonic applications, there has not been much consideration on improving the near-field optical performance of the system by engineering the near-field sample. In this work, we demonstrate the impact of tailoring the near-field sample by studying an emerging plasmonic application, namely heat-assisted magnetic recording. Basic principles of Maxwell's and heat transfer equations are utilized to obtain a magnetic medium with superior optical and thermal performance compared to a conventional magnetic medium.
Near-Field Radiation from Nano-Particles and Nano-Antennas Illuminated with a Focused Beam of Light
Authors: Sendur Kursat , Sahinoz Ahmet , Unlu Eren , Yazici Serkan , Gulhan Mert 
Published: August 2010

AbstractThe interaction of photons with metallic nanoparticles and nanoantennas yields large enhancement and tight localization of electromagnetic fields in the vicinity of nanoparticles. In the first part of this study, the interaction of a spherical nanoparticle with focused beams of various angular spectra is investigated. This study demonstrates that the focused light can be utilized to manipulate the near-field radiation around nanoparticles. In the second part of this study, the interaction between linearly and radially polarized focused light with prolate spheroidal nanoparticles and nano-antennas is investigated. Strong and tightly localized longitudinal components of a radially polarized focused beam can excite strong plasmon modes on elongated nanoparticles such as prolate spheroids. The effect of a focused beam on parameters such as the numerical aperture of a beam and the wavelength of incident light, as well as particle geometry and composition are also studied.
The Structural Phase Transition in Individual Vanadium Dioxide Nanoparticles
Authors: Rivera Felipe , Davis Robert C. , Vanfleet Richard 
Published: August 2010

AbstractVanadium dioxide (VO2) single crystals undergo a structural first-order metal to insulator phase transition at approximately 68°C. This phase transition exhibits a resistivity change of up to 5 orders of magnitude in bulk specimens. We observe a 2-3 order of magnitude change in thin films of VO2. Individual particles with sizes ranging from 50 to 250 nm were studied by means of Transmission Electron Microscopy (TEM). The structural transition for individual particles was observed as a function of temperature. Furthermore, the interface between grains was also studied. We present our current progress in understanding this phase transition for polycrystalline thin films of VO2 from the view of individual particles.
Quantitative Scanning Transmission Electron Microscopy for the Measurement of Thicknesses and Volumes of Individual Nanoparticles
Authors: Heinrich Helge , Yuan Biao , Nukala Haritha , Yao Bo 
Published: August 2010

AbstractIn Scanning Transmission Electron Microscopy (STEM) the High-Angle Annular Dark-Field (HAADF) signal increases with atomic number and sample thickness, while dynamic scattering effects and sample orientation have little influence on the contrast. The sensitivity of the HAADF detector for a FEI F30 transmission electron microscope has been calibrated. Additionally, a nearly linear relationship of the HAADF signal with the incident electron current is confirmed. Cross sections of multilayered samples for contrast calibration were obtained by focused ion-beam (FIB) preparation. These cross sections contained several layers with known composition. A database with several pure elements and compounds has been compiled, containing experimental data on the fraction of electrons scattered onto the HAADF detector for each nanometer of sample thickness. Contrast simulations are based on the multi-slice formalism and confirm the differences in HAADF-scattering contrast for the elements and compounds. TEM offers high lateral resolution, but contains little or no information on the thickness of samples. Thickness maps in energy-filtered transmission electron microscopy, convergent-beam electron diffraction and tilt series are so far the only methods to determine thicknesses of particles in a transmission electron microscope. We show that the calibrated HAADF contrast can be used to determine the thicknesses of individual nanoparticles deposited on carbon films. With this information the volumes of nanoparticles with known composition were determined.
Size, Stability and Chemistry of Nanomaterials and their Precursors by Mass Spectrometry Techniques
Authors: Gaumet Jean Jacques , Arl Didier , Dalmasso Stéphane , Aubriet Frédéric , Laurenti Jean-Pierre 
Published: August 2010

AbstractSoft ionization mass spectrometry (MS) methods [Electro-Spray Ionisation - Fourier Transform Ion Cyclotronic Resonance MS (ESI-FTICRMS) and Matrix Assisted Laser Desorption Ionization coupled with Time of Flight MS (MALDI-TOFMS)] and associated fragmentation techniques appear to be an alternative way providing data on the size, stability and exact chemical composition of nanoparticles and their precursors, and potentially on interactions between particles. We report the application of both mass spectrometry techniques to analyze II-VI semiconductor nanomaterials (CdX with X = S or Se) and their organometallic precursors.
Composition Quantification of Microelectronics Multilayer Thin Films by EDX: Toward Small Scale Analysis
Authors: Conard Thierry , Arstila Kai , Hantschel Thomas , Franquet Alexis , Vandervorst Wilfried , Vecchio Emma , Burgess Simon , Bauer Frank 
Published: August 2010

AbstractIn order to continuously improve the performances of microelectronics devices through scaling, SiO2 is being replaced by high-k materials as gate dielectric; metal gates are replacing poly-Si. This leads to increasingly more complex stacks. For future generations, the replacement of Si as a substrate by Ge and/or III/V material is also considered. This also increases the demand on the metrology tools as a thorough characterization, including composition and thickness is thus needed. Many different techniques exist for composition analysis. They usually require however large area for the analysis, complex instrumentation and can be time consuming. EDS (Energy Dispersive Spectroscopy) when coupled to Scanning Electron Microscopy (SEM) has the potential to allow fast analysis on small scale areas.In this work, we evaluate the possibilities of EDS for thin film analysis based on an intercomparison of composition analysis with different techniques. We show that using proper modeling, high quality quantitative composition and thickness of multilayers can be achieved.
Methods to Measure Mechanical Properties of NEMS and MEMS: Challenges and Pitfalls
Authors: De Wolf Ingrid , Kalicinski Stanislaw , De Coster Jeroen , Oprins Herman 
Published: August 2010

AbstractThis paper focuses on the measurement of material properties of micro and nano-electromechanical systems. Two different methods are discussed: electrical or optical measurements of the resonance frequency, and measurements of the Raman frequency shift. The main focus of this paper is on challenges and pitfalls related to the use of these techniques for the study of MEMS and NEMS.
On the effects of dislocation density on micropillar strength
Authors: Benzerga Amine 
Published: August 2010

AbstractThere is an increasing amount of experimental evidence that the plastic behavior of crystals changes at micro- and nano-scales in a way that is not necessarily captured by state-of-the-art plasticity models. In this paper, length scale effects in the plasticity of crystals are analyzed by means of direct numerical simulations that resolve the scale of the carriers of plasticity, i.e., the dislocations. A computationally efficient, atomistically informed dislocation dynamics framework which has the capability of reaching high dislocation densities and large strains at moderately low strain rates in finite volumes is recalled. Using this theoretical framework, a new type of size effect in the hardening of crystals subject to nominally uniform compression is discovered. In light of such findings, behavior transitions in the space of meaningful structural parameters, from forest-hardening dominated regime to an exhaustion hardening dominated regime are discussed. Various scalings of the flow stress with crystal size emerge in the simulations, which are compared with recent experimental data on micro- and nano-pillars.
Stress-strain behavior of individual electrospun polymer fibers using combination AFM and SEM
Authors: Hang Fei , Lu Dun , Li Shuang Wu , Barber Asa H 
Published: August 2010

AbstractTensile deformation of individual electrospun polyvinyl alcohol (PVA) nanofibres was performed using a novel combination atomic force microscope (AFM)- scanning electron microscope (SEM) technique. The AFM was used to provide manipulation and mechanical testing of individual PVA nanofibers while the SEM was used to observe the deformation process. Resultant stress-strain curves show how the elastic modulus shows comparable, or even slightly increased, values to isotropic films. In addition, the electrospun fibers were tested to failure to measure their tensile strength.
Iron oxide crystal formation on a substrate modified with the Mms6 protein from magnetotactic bacteria
Authors: Arakaki Atsushi , Masuda Fukashi , Matsunaga Tadashi 
Published: August 2010

AbstractMms6 is a small acidic protein which is tightly bound to magnetite in the bacterium Magnetospirillum magneticum AMB-1. Mms6 has been previously shown to promote iron-binding capacity as well as modulate the size and morphology of magnetic iron oxide crystals in vitro. In this study, we synthesized iron oxide crystals by using a monolayer-modified substrate. A self-assembled monolayer of octadecyltrimethoxysilane was modified on a silicon substrate. Recombinant Mms6 protein was attached to the substrate through the hydrophobic interactions between the protein molecules and the monolayer. The immobilization of protein molecules on the substrate surface was confirmed by fluorescent labeling of these molecules and subsequent fluorescence microscopy. This protein-modified substrate was then used as a template for iron oxide crystal formation in a ferrous solution. Scanning electron microscopy revealed site-specific formation of iron oxide crystals in substrate regions with immobilized proteins. This use of proteins might provide an alternative method for the bottom-up fabrication of nano-sized magnetic particles.
Nanosilica Formation at Lipid Membranes Induced by Silaffin Peptides
Authors: Kent Michael , Murton Jaclyn K. , Satija Sushil , Kuzmenko Ivan , Simmons Blake 
Published: August 2010

AbstractDiatoms are unicellular eukaryotic algae found in fresh and marine water. Each cell is surrounded by an outer shell called a frustule that is composed of highly structured amorphous silica. Diatoms are able to transform silicic acid into these sturdy intricate structures at ambient temperatures and pressures, whereas the chemical synthesis of silica-based materials typically requires extremes of temperature and pH. Cationic polypeptides, termed silica affinity proteins (or silaffins) recently identified from dissolved frustules of specific species of diatoms are clearly involved and have been shown to initiate the formation of silica in solution. The relationship between the local environment of catalytic sites on these peptides, which can be influenced by the amino acid sequence and the extent of aggregation, and the observed structure of the silica is not understood. Moreover, the activity of these peptides in promoting silicification at lipid membranes has not yet been clarified. In this work we developed a model system to address some of these questions. We studied peptide adsorption to Langmuir monolayers and subsequent silicification using X-ray reflectivity and grazing incidence X-ray diffraction. The results demonstrate the lipid affinity of the parent sequences of several silaffin peptides. Further, the results show that the membrane-bound peptides promote the formation of interfacial nanoscale layers of amorphous silica at the lipid-water interface that vary in structure according to the peptide sequence.
Structural and Electrical Characterization of Diatom Pinnularia sp. Biosilica Coated with CdS Thin Film
Authors: Gutu Timothy , Jeffryes Clayton , Wang Wei , Chang Chih-hung , Rorrer Gregory , Jiao Jun 
Published: August 2010

AbstractDiatoms are unicellular, photosynthetic microalgae that live in marine and freshwater environments. The cell walls of diatoms are composed of biosilica and have exceedingly hierarchical ornate nanostructures. Consequently, these nanostructures have long been regarded as the paradigm for future silica nanotechnology. We have coated diatom Pinnularia sp. biosilica with a thin film of CdS using a chemical bath deposition technique. Possible uses for these CdS coated diatoms include the development of new nanodevice fabrication techniques and optoelectronic applications. Electron microscopy techniques were utilized to study their morphologies. Their electrical characteristics were investigated using an Agilent 4156C precision semiconductor parameter analyzer and a Cascade probe station. The CdS coating was found to be dense, adherent and nanostructured. The diatoms coated with CdS exhibited both metallic and semiconductor diode behavior.
Catalytic Forming Gas Anneal on III-V/Ge MOS Systems
Authors: Wang Wei-E , Lin Han-Chung , Brammertz Guy , Delabie Annelies , simoen eddy , Caymax Matty , Meuris Marc , Heyns Marc 
Published: August 2010

AbstractCatalytic-FGA, a combination of the standard forming gas anneal with a catalytic metal gate, has been applied to study the hydrogen passivation of III-V/Ge MOS systems. Pd (or Pt) metal gate catalytically dissociates molecular hydrogen into atomic hydrogen atoms, which then diffuse through the dielectric layer and neutralize certain semiconductor/dielectric interfacial defects. MOS systems with various interfacial qualities, including lattice-matched (n/p) In0.53Ga0.47As/10nm ALD-Al2O3 (or ZrO2)/Pd capacitors, an undoped Ge/˜1nm GeO2/4nm ALD-Al2O3/Pt capacitor, and an nGe/8nm ALD-Al2O3/Pt capacitor are fabricated to evaluate the effectiveness of C-FGA.
Ultrafast Self-Assembly of Microscale Particles by Open-Channel Flow
Authors: Choi Sun , Pisano Albert P. , Zohdi Tarek I. 
Published: August 2010

AbstractWe developed an ultrafast microfluidic approach to self-assemble microparticles in threedimensions by taking advantage of simple photolithography and capillary action of microparticle-dispersed suspensions. The experimental verifications of the assembly of various sizes of silica microspheres and silica gel microspheres within thin and long open microchannels by using this approach have been demonstrated. We anticipate that the presented technique will be widely used in semiconductor and Bio-MEMS (microelectromechanical Systems) fields because it offers a fast way to control 3D, microscale particle assemblies and also has superb compatibility with photolithography, which can lead to an easy integration of particle assembly with existing CMOS (complementary metal-oxide-semiconductor) and MEMS fabrication processes.
Organic Thin Film Transistors based on Pentacene and PTCDI as the Active Layer and LiF as the Insulating Layer
Authors: Rahimi Ronak , Korakakis D. 
Published: August 2010

AbstractDue to the advantages of low production cost, flexibility and low temperature fabrication, much effort has been devoted to the development of organic electronic devices such as light emitting diodes, photovoltaics and transistors. Organic thin film transistors have several important applications such as switching devices for active-matrix OLED displays, smart cards, identification tags and sensors [1-3]. However, the low carrier mobility in organic materials and the difficulty of integrating organic devices into inorganic processing procedures have hindered the development of organic transistors that are comparable to traditional transistors [4]. Much effort has been devoted to develop new organic materials with higher carrier mobility, while retaining the same conventional inorganic metal-oxide-semiconductor structures.Lithium fluoride (LiF) has the largest band gap and the largest negative electron affinity of any solid, [5] making it a superb candidate for use in the insulating layer of transistors. Using LiF as the gate dielectric layer can facilitate the organic transistor fabrication. In this work, thin film transistors based on pentacene and PTCDI-C8 (N,N′-Dioctyl-3,4,9,10-perylenedicarboximide) as organic semiconductor layers and LiF as gate dielectrics are studied. The electrical properties of these devices have been investigated in atmospheric conditions and under variable light exposure. Output and transfer characteristics of several photo-responsive thin film transistors using different organic materials but with the same insulating layer will be presented and the increase of drain-source current upon illumination will be discussed based on the photoconduction properties of the transistor active layer.
The Salt and Paper Battery; Ultrafast and All-polymer Based
Authors: Nyström Gustav , Razaq Aamir , Mihranyan Albert , Nyholm Leif , Strømme Maria 
Published: August 2010

AbstractWe have recently developed a flexible battery using two common, inexpensive ingredients: cellulose and salt. This lightweight, rechargeable battery uses thin pieces of paper—originating from cellulose fibers from the environmentally polluting Cladophora sp.algae—as electrodes, while a solution of sodium chloride acts as the electrolyte. Conducting polymers for battery applications have been subject to numerous investigations during the last decades. However, the functional charging rates and the cycling stabilities have so far been found to be insufficient for practical applications. These shortcomings can, at least partially, be explained by the fact that thick layers of the conducting polymers have been used to obtain sufficient capacities of the batteries. We now introduce a novel nanostructured high-surface area electrode material for energy storage applications composed of cellulose fibers of algal origin individually coated with a 50 nm thin layer of polypyrrole. Our results show the hitherto highest reported charge capacities and charging rates for an all polymer paper-based battery. The composite conductive paper material is shown to have a specific surface area of 80 m2/g and batteries based on this material can be charged with currents as high as 600 mA/cm2. The aqueous-based batteries, which are entirely based on cellulose and polypyrrole and exhibit charge capacities between 25 and 33 mAh/g or 38-50 mAh/g per weight of the active material, open up new possibilities for the production of environmentally friendly, cost efficient, up-scalable and lightweight energy storage systems.
A Theoretical Study and Realization of New Spin Quantum Cross Structure Devices using Organic Materials
Authors: Kondo Kenji , Kaiju Hideo , Ishibashi Akira 
Published: August 2010

AbstractWe have proposed a spin quantum cross structure (SQCS) device as a candidate beyond CMOS. The SQCS device consists of two ferromagnetic metal thin films with their edges crossed, and sandwiches a few atoms or molecules. In this work, the spin dependent transport formula has been derived for SQCS devices with collinear ferromagnetic electrodes within the framework of the Anderson Hamiltonian. Also, the calculation of the magnetoresistance (MR) ratio has been done as a function of renormalized transfer matrices including magnetostriction effects and the other effects phenomenologically. It is shown that the MR ratio can be controlled by changing the renormalized coupling constants. The MR ratio is represented by a new formula. Also, we have realized an SQCS device with Ni magnetic thin-film electrodes, sandwiching poly (3-hexylthiophene) (P3HT): 6, 6-phenyl-C61-butyric acid methyl ester (PCBM) organic molecules between both the electrodes. The current-voltage characteristics of SQCS devices were measured by a four-terminal method and agree well with the theoretical results, quantitatively.
Development of PLZT Film-on-Foil Capacitors with High Dielectric Strength
Authors: Ma Beihai , Narayanan Manoj , Balachandran U. 
Published: August 2010

AbstractFerroelectric film-on-foil capacitors hold special promise to replace discrete passive components in the development of electronic devices that require greater performance and smaller size. We have grown ferroelectric Pb0.92La0.08Zr0.52Ti0.48O3(PLZT) films on nickel substrates by chemical solution deposition. The dielectric properties were determined for samples of ≈1.15-μm-thick PLZT film grown on LaNiO3-buffered nickel substrates. Measurements on these samples yielded a dielectric constant of ≈1300, dielectric loss (tan δ) of ≈0.05, and leakage current density of ≈7 × 10-9A/cm2. An energy density of ≈74 J/cm3was measured at room temperature with 250-μm-diameter capacitors. Highly accelerated lifetime tests were conducted at 100°C to determine the reliability of the ≈1.15-μm-thick film-on-foil capacitors under field stress conditions (with applied electric field from 8.7 × 105V/cm to 1.3 × 106V/cm). The breakdown behavior of the PLZT film-on-foil capacitors was evaluated by Weibull analysis. A voltage acceleration factor of ≈-6.3 was obtained. From the test results, a mean time to failure of >3000 hr was projected for capacitors operated at 100°C with ≈2.6 × 105V/cm dc electric field.
Fabrication and Characterization of Artificially Designed PZT/LSMO Multiferroics Heterostructure
Authors: Dussan Sandra , Kumar Ashok , Katiyar Ram S. 
Published: August 2010

AbstractHighly oriented and epitaxial bilayers of PbZr0.52Ti0.48O3/La0.67Sr0.33MnO3 (PZT/LSMO) thin films have been grown by pulsed laser deposition on two different substrates (100) - MgO and -LaAlO3 (LAO) respectively. The structural analysis using X-ray diffraction (XRD) evidenced that layered structure was formed without any secondary phase. Atomic force microscopy (AFM) images shown change in the grain size and surface roughness with change of the substrate. Room temperature magnetization-field (M-H) exhibited well-shaped magnetization hysteresis loops, good saturation and low coercivity. The electrical properties of hetrostructure exhibited high remnant polarization (30-54 μC/cm2) and dielectric constant (400-1700) depending upon the different substrate and temperature deposition of FM layer. Frequency dependent change in dielectric constant and loss were observed above metallic ferromagnet to insulator paramagnet transition temperature. It is important to note that the frequency dependent dielectric anomalies are attributed to the change in metallic nature of LSMO bottom electrode and also the bilayer.