bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vertically Aligned CNTs Embedded in Cr/TiO2 Membranes For Realization of Ion Sources
Authors: Abdi Yaser , Sadeghi Mehdi , Mohajerzadeh Shams , Koohsorkhi Javad , Hekmat-Shoar Bahman 
Published: April 2011

AbstractPECVD-grown carbon nanotubes on (100) silicon membranes have been realized and exploited for electron and ion emission applications. The growth of CNT's is achieved by a mixture of hydrogen and acetylene gases in a CVD reactor and a 5-10nm thick nickel is used as the seed for the growth. The presence of a DC-plasma yields a vertical growth of carbon nanotubes. The as-grown nanotubes are encapsulated by means of an insulating TiO2 layer. The formation of a thin membrane is possible by means of a chemical anisotropic etching technique. The membrane is then removed from the back side to fully suspend the CNT-holding TiO2 layer. Upon exposure to a plasma ashing step the nanotubes are partially removed and a both-end opened hollow nanostructure is formed which can be used as a miniaturized ion source. The CNT-holding substrate can be exploited as a grid to extract the ions from an ionization chamber just underneath the membrane. Applying a proper accelerating electric field, positive ions made inside a DC discharge cavity can form a beam-shape emission of ions towards the opposite negative electrode. The beam is well suited for a source of ion lithography. In which, the emission has the ability of direct writing on a photo-resist coated substrates. Preliminary nano-scale dots have been created with sizes between 50 and 80nm. Scanning electron microscopy has been used to investigate the results.
TEM Observations of Bio-Conjugated Streptavidin-Gold Nanoparticles
Authors: Koh Ai Leen , Sinclair Robert 
Published: April 2011

AbstractSimultaneous visualization of inorganic nanoparticles and their bio-functionalized coating under the TEM can be achieved with negative staining, where electron dense material is introduced onto the specimen to enhance contrast. Using this technique, streptavidin-functionalized gold nanoparticles were negatively stained using phosphotungstic acid (PTA) at pH 7.0 and then observed using the TEM. The proteins appear as light regions/halos surrounding the gold nanoparticles, with widths similar to those of streptavidin protein molecules reported in literature. Experiments were performed to bio-conjugate streptavidin-gold nanoparticles to biotinylated antibodies and biotinylated actin, and then negatively staining the samples with PTA for TEM analyses. In the first experiment, an increase in halo widths in more than 60% of the particles was observed. In the second experiment, the nanoparticles were found to localize around the long actin filaments. Negative staining is useful for studying bio-functionalized nanoparticles as it enables the proteins surrounding the nanoparticles to be imaged and studied using the TEM.
Non-invasive high-resolution acoustic microscopy technique using embedded nanostructures
Authors: Wulin Daniel , Ramanathan Shriram 
Published: April 2011

AbstractAn opto-acoustic system capable of operating at frequencies greater than 1 GHz with novel biological applications is proposed for the first time. Metallic spheres with radii on the order of hundreds of nanometers dispersed inside a bio-matrix can be used to generate in-situ ultra-high frequency acoustic waves whose normal mode frequencies can be calculated using Lamb's theory for acoustic oscillations of elastic spheres. The frequency and amplitude of the resulting acoustic waves can be related to the physical properties of the metallic spheres and the surrounding bio-matrix: the acoustic waves produced by the metallic spheres are well-suited to high resolution acoustic imaging. We anticipate that our approach will open up new nanoscale techniques to study cells non-invasively.
Magnetic Hyperthermia Study of Mn-Zn-Fe and Zn-Gd-Fe Nanoparticle Systems as Possible Low-Tc Agents for Magnetic Particle Hyperthermia
Authors: Hayek Saleh S. , Chen Ching-Jen , Flores Glen , Batich Christopher D. , Haik Yousef S. 
Published: April 2011

AbstractMagnetic nanoparticles have found utility in many biological applications, including imaging, cancer therapy, drug delivery, sensing and hyperthermia for tumor therapy. Hyperthermia is raising the tissue temperature between 41.5 - 46 degrees Celsius to kill cancerous cells while preserving the normal cells. Due to the fact that many robust synthetic strategies exist for iron oxides which results in high quality, monodisperse and crystalline nanoparticles, hyperthermia applications have traditionally used magnetic oxide nanoparticles. On the other hand, new materials for hyperthermia that combine the advantages of stability with those of magnetic behavior are desirable. We report the synthesis of MnZnFe, CoGdZn and ZnGdFe nanoparticle systems which are ideal for biological applications over magnetic oxides due to their conjugation chemistry, and surface chemistry. We present an AC magnetic heating studies of these nanoparticle systems which exhibit magnetic field heating. The frequency dependence of the heating follows general trends predicted by power loss equations and is similar to traditional materials. The heating pattern of Zn-Gd-Fe (20mg/ml) using alcohol thermometer at 961 kHz and 433 KHz and the heating pattern of Mn-Zn-Fe [Zn = 0.5 conc.](20mg/ml) using alcohol thermometer at 961 kHz and finally the heating pattern of Co-Gd Zn [Zn = 0.2 conc. Gd (1-X)] (20mg/ml) using alcohol thermometer at 961 kHz are reported. X Ray Diffraction studies and SQUID magnetic measurements and TEM and EDX particle size and constituents measurements are also included for the nanoparticle systems. In conclusion, high quality heating nanoparticle composites were developed for hyperthermia treatment of cancer. The composites generate sufficient heat at room temperature and stops heating at the Curie temperature Tc of the respective nanoparticle system.
Enhancing the Biological Stability and Functionalities of Quantum Dots via Compact Multifunctional Ligands
Authors: Susumu Kimihiro , Pons Thomas , Medintz Igor L. , Mattoussi Hedi 
Published: April 2011

AbstractWe have designed and synthesized a series of modular ligands based on poly(ethylene glycol) (PEG) coupled with functional terminal groups to promote biocompatibility of water-soluble quantum dots (QDs). Each hydrophilic ligand is comprised of three modules: a PEG single chain to promote hydrophilicity, dihydrolipoic acid (DHLA) unit connected to one end of the PEG chain for strong anchoring on the QD surface, and potential biological functional groups (biotin, amino, and carboxyl groups) at the other end of the PEG. Water-soluble QDs capped with one type or mixtures of the functional ligands were prepared via cap exchange with the native hydrophobic caps. Homogeneous QD solutions that are stable over extended periods of time and over broad pH range were prepared. Surface binding assay showed that DHLA-PEG-biotin-functionalized QDs strongly interacted with NeutrAvidin-modified surfaces. The new functional surface ligands studied here provide not only stable and highly water-soluble QDs but also simple and easy access to various biological entities.
Swift Heavy Ion Beam-Based Nanopatterning Using Self-Assembled Masks
Authors: Jensen Jens , Sanz Ruy , Skupinski Marek , Hernandez-Vélez Manuel , Possnert Göran , Hjort Klas 
Published: April 2011

AbstractSwift heavy ion beam-based lithography using masks of self-assembled materials has been applied for transferring well-ordered micro- and nanopatterns to rutile TiO2 single crystals. As the induced damage has a high etching selectivity the patterns can be developed in HF with very high contrast. Here we present resulting patterns when using a mask of self-ordered silica spheres. Since the obtained structures are replicas of the mass distribution of the applied mask, the shape and size of resulting structures depend on the geometric configuration of the silica sphere layers. In addition, the resulting pattern can be tuned by varying the applied ion energy and fluence. Direct modifications of the optical properties of TiO2 in a well-defined pattern are also presented.
Nano-film and Coating for Biomedical Application Prepared by Plasma-based Technologies
Authors: Liu Xuanyong , Chu Paul K 
Published: April 2011

AbstractNanosized materials have been widely applied in biomedical engineering due to their unique nano-effects. In this work, nano-TiO2 coatings and ZrO2 films were prepared using plasma technologies including plasma spraying and cathodic arc plasma deposition. The microstructure the coatings and films were assessed using TEM, SEM, and AFM. Their bioactivity and biocompatibility were evaluated using simulated body fluid soaking tests and cell culturing. Films and coatings with nanostructured surfaces can be obtained using plasma spraying and cathodic arc plasma deposition. The nanostructured surfaces can endow the films and coatings excellent bioactivity and biocompatibility. The UV-illuminated and hydrogen implanted nano-TiO2 coatings and ZrO2 films can induce bone-like apatite formation on their surfaces after immersion in a simulated body fluid for a certain period of time. The nano-TiO2 coating has better cytocompatibility than the micro-TiO2 coating, and the cytocompatibility can be improved by UV-illumination and hydrogen implantation. The bioactivity of the ZrO2 thin film deteriorates after thermal treated. The size of the particles on the surface of the film is thought to be one of the key factors responsible for the bioactivity.
Effects of MeV Si ion bombardments on the Properties of Nano-layers of SiO2/SiO2+Zn4Sb3
Authors: Budak S. , Guner S. , Muntele C. , Smith C. C. , Zimmerman R. L. , ILA D. 
Published: April 2011

AbstractWe prepared 8 periodic nano-layers of SiO2/SiO2+Zn4Sb3. The deposited multi-layer films have a periodic structure consisting of alternating layers where each layer is between 1-10 nm thick. The purpose of this research is to generate nanolayers of nanostructures of Zn4Sb3 with SiO2 as host and as buffer layer using a combination of co-deposition and MeV ion bombardment taking advantage of the electronics energy deposited in the MeV ion track due to ionization in order to nucleate nanostructures. The electrical and thermal properties of the layered structures were studied before and after bombardment by 5 MeV Si ions at various fluences to form nanostructures in layers of SiO2 containing Zn4Sb3. Rutherford Backscattering Spectrometry (RBS) was used to monitor the stoichiometry before and after MeV bombardments.
Capillary Kinetics of Thin Polymer Films in Permeable Microcavities
Authors: Suh Kahp-Yang 
Published: April 2011

AbstractWe present a Poiseuille model that can explain the rate of capillary rise of thin polymer films in permeable microcavities. In comparison to the traditional Poiseuille formulation, two unique features of the system were considered: the permeable nature of the enclosure and the effect of thin polymer films that are confined to the substrate. The model predicts that the rate is inversely proportional to the channel width, contrary to what the original Poiseuille model predicts, and it is proportional to the initial film thickness, which the original model cannot account for. The modified model is in satisfactory agreement with experimental data.
Characterization of Heat Propagation along Single Tin Dioxide Nanobelt Using the Thermoreflectance Method
Authors: Wang Xi , Ezzahri Younes , Christofferson James , Zhang Yi , Shakouri Ali , Shi Li , Yu Choongho , Wang Zhong Lin 
Published: April 2011

AbstractIn this paper, we studied heat transfer properties of a 230nm wide，450nm thick and 5.4 m long single tin dioxide nanobelt using non-contacted high resolution thermoreflectance imaging technique. Temperature difference across the nanobelt was created by attaching its both ends to a microfabricated thin film heater and sensor pair. High resolution thermal images of the nanobelt and thin film devices were obtained at variant pulsing current amplitudes and frequencies, which allowed us to study the inherent thermal conductance of the nanobelt. Thermal expansion induced thermoreflectance coefficient change is also discussed in this paper.
Thermal Conductivity Measurement of Cu Thin Films using Radiation Heat Exchange Method
Authors: Ryu Sang , Kim Youngman , Juhng Woonam 
Published: April 2011

AbstractA measurement method of thermal conductivities of Cu thin films was devised from the temperature distributions of substrate surfaces. The substrate was prepared to have a prismatic bar shape, and was deposited with Cu thin films using sputtering. Two metal coated surfaces of specimens were brought into contact to maintain the insulated boundary condition. Specimens were heated with constant temperature at both ends. The temperature distributions were measured from the back surface of substrate using a radiation thermometry.The thermal conductivities of Cu thin films were found to be much lower than those of bulk materials. Wiedemann-Franz law could be applied to thin films produced in this study. Thermal conductivity was also estimated from the resistivity of thin film and Lorenz number of bulk material.
Creating Dense, Constrained Ce0.9Gd0.1O1.95Films at Low Temperature for SOFC Applications
Authors: Nicholas Jason D. , De Jonghe Lutgard C. 
Published: April 2011

AbstractWe have investigated the effect of various dopants on the sintering characteristics of Ce0.9Gd0.1O1.95(CGO) and found that 99% dense electrolyte pellets can be produced at the record low temperature of 800°C (as opposed to the 1400°C typically needed) by sintering Ce0.9Gd0.1O1.95with as little 3mol% lithium. Our studies indicate that doping the CGO surface with lithium nitrate, as opposed to using alternative lithium salts, produces the largest decrease in sintering temperature. Unlike other dopants that lower the sintering temperature by altering the near grain boundary vacancy concentration, lithium lowers the sintering temperature through the formation of an intergranular liquid phase. This liquid phase allows fully dense, completely constrained CGO films to be produced on inert substrates at temperatures as low as 950°C.
Anodization of Sputtered Titanium Films
Authors: Dhawan Deepak , Bhargava Suresh K. , Wlodarski Wojtek , Kalantar-zadeh Kourosh 
Published: April 2011

AbstractNanoporous Ti (and TiOx) has been formed by anodization of RF sputtered titanium thin films. A solution of 1M (NH4)2SO4 (ammonium sulphate) electrolytes containing 0.5wt% (NH4)F (ammonium fluoride) was used in the anodization process. Different nano and micro structures were obtained. Voltage in a rage of 2 to 10V was employed in the process. It was observed that the magnitude of applied voltage have a significant impact in the formation of different surface morphologies with various nano/micro structures. The anodized titanium thin films were characterised using scanning electron microscopy and X-ray diffraction techniques.
Combinatorial Searching for Noble Metal-based Thin Film Amorphous Alloys for Glass Lens Mold
Authors: Sakurai Junpei , Hata Seiichi , Yamauchi Ryusuke , Tachikawa Hiroyuki , Shimokohbe Akira 
Published: April 2011

AbstractThis paper presents the properties of Pt-based thin film amorphous alloys developed for a glass lens mold. To search for the amorphous alloys, Pt-Zr-Ni and Pt-Hf-Ni thin film libraries were fabricated using combinatorial arc plasma deposition (CAPD). The composition ranges of the amorphous region in each library were 50 to 60 at.% Pt, 0 to 20 at.% Ni, and balance being Zr or Hf. To evaluate the thermal and mechanical properties of these amorphous alloys, Pt51Zr39Ni10 and Pt52Hf36Ni12 samples, as typical amorphous samples, were prepared by sputtering. The Pt51Zr39Ni10 sample showed a crystallization temperature, Tx, of 939 K and a fracture stress, σf, of 1.44 GPa. The Pt52Hf36Ni12 sample showed a Tx of 978 K and a σf of 0.3 GPa. The Pt51Zr39Ni10 and Pt52Hf36Ni12 samples did not achieve the target Tx (973K) and σf (1.0 GPa). In order to achieve the target properties, Zr was displaced with Hf to increase the Tx of Pt-Zr-Ni and four Pt51HfxZr37-xNi12 samples were prepared. The Pt51Hf20Zr17Ni12 sample had a Tx of 992 K and a σf of 0.87 GPa, and almost achieved the target properties. The machinability of the Pt51Hf20Zr17Ni12 sample was also evaluated. Though this sample could be cut using a diamond tool, it did not show sufficient machinability. In order to improve the accuracy of the glass mold shape, the machinability of the Pt-based thin film amorphous alloys require further modification.
An Autonomous and Intelligent System Using Mobile-Agent Software to Model the Calculation Processes of Film Deposition Simulators
Authors: Takahashi Takahiro , Fukui Noriyuki , Arakawa Masamoto , Funatsu Kimito , Ema Yoshinori 
Published: April 2011

AbstractWe developed an autonomous modeling system for the calculation processes of the simulator for film deposition processes in order to decrease the calculation cost for reproducing experimental results. Replacing the simulator with the mathematical models proposed by the modeling system decreased huge calculation cost of the simulator. The system consists of onemobile agentand three platforms for the agent. The agent autonomously moved in the computer-networks and operated the process simulator in the platform in order to make training data needed for modeling and then operated the generalized modeling software in the platform using the training data and finally the agent created the models. The models showed both good reproducibility and predictability with the calculated results of the simulator.
Stress distribution in polycrystalline silicon thin film solar cells on glass measured by micro-Raman spectroscopy
Authors: Sarau George , Becker Michael , Berger Andreas , Schneider Jens , Christiansen Silke 
Published: April 2011

AbstractMicro-Raman spectroscopy is used to measure stress distributions in 1.5 µm thick polycrystalline silicon thin film solar cells on glass. These measurements are combined with transmission electron microscopy and atomic force microscopy to assign the measured local stresses to the sample's microstructure. Expansion and contraction of the silicon lattice in the layer and the borosilicate glass substrate during the thermal processing of the solar cell as well as quartz beads of µm size that reside on the glass substrate for light-trapping purposes induce internal stresses that locally vary with structural features. While the thermal processing induces an average tensile stress in the silicon layer originating from the thermal mismatch between glass and silicon, the latter results in lateral stress gradients up to 208 ± 12 MPa in the mapped area.
Oxidation Kinetics of Cu-Ni Alloy Observed by in situ UHV-TEM
Authors: Sun Li , Pearson John E. , Yang Judith C. 
Published: April 2011

AbstractThe nucleation and growth of Cu2O and NiO islands due to oxidation of Cu-24%Ni(001) films were monitored at various temperatures by in situ ultra-high vacuum (UHV) transmission electron microscopy (TEM). In remarkable contrast to our previous observations of Cu and Cu-Au oxidation, irregular-shaped polycrystalline oxide islands were observed to form with respect to the Cu-Ni alloy film, and an unusual second oxide nucleation stage was noted. Similar to Cu oxidation, the cross-sectional area growth rate of the oxide island is linear indicating oxygen surface diffusion is the primary mechanism of oxide growth.
EMCD: Magnetic Chiral Dichroism in the Electron Microscope
Authors: Rubino Stefano , Schattschneider Peter , Stöger-Pollach Michael , Hébert Cécile , Rusz Ján , Calmels Lionel , Warot-Fonrose Benedicte , Houdellier Florent , Serin Virginie , Novàk Pavel 
Published: April 2011

AbstractA new technique called Energy-loss Magnetic Chiral Dichroism (EMCD) has recently been developed [1] to measure Magnetic Circular Dichroism (MCD) in the Transmission Electron Microscope (TEM) with a spatial resolution of 10 nm. This novel technique is the TEM counterpart of X-ray Magnetic Circular Dichroism (XMCD), which is widely used for the characterization of magnetic materials with synchrotron radiation.In this paper we describe several experimental methods which can be used to measure the EMCD signal [1-5] and give a review of the recent improvements of this new investigation tool. The dependence of the EMCD on several experimental conditions (such as thickness, relative orientation of beam and sample, collection and convergence angle) is investigated in the transition metals Iron, Cobalt and Nickel. Different scattering geometries are illustrated; their advantages and disadvantages are detailed, together with current limitations. The next realistic perspectives of this technique will consist in measuring atomic specific magnetic moments, using suitable spin and orbital sum rules [4,6], with a resolution down to 2-3 nm.
Imaging Oxide-Covered Doped Silicon Structures Using Low-Energy Electron Microscopy
Authors: Anderson Meredith , Nakakura C.Y. , Saiz K.F. , Kellogg G.L. 
Published: April 2011

AbstractLow energy electron microscopy (LEEM) operated at incident electron energies just above the “mirror” mode is used to image Si-based test devices. Significant p- vs. n- doping contrast is observed, even when the structures are covered with a ∼3.5 nm thermal oxide. The contrast arises from a difference in surface potential between the two regions and is related to both p-n work function differences and electron-beam-induced charging of the oxide. The results show that the LEEM is capable of characterizing pn junctions without complicated sample preparation and that it is a promising technique for rapid, non-destructive imaging of microelectronic devices.
Nanoparticle suspensions studied by x-ray photon correlation spectroscopy
Authors: Lu Xinhui , Mochrie Simon G. J. , Narayanan S. , Sandy Alec R. , Sprung Michael 
Published: April 2011

AbstractMultispeckle x-ray photon correlation spectroscopy measurements, carried out at beamline 8-ID at the Advanced Photon Source at Argonne National Laboratory, of opaque suspensions of silica nanoparticles in water and lutidine-water binary mixtures are presented.
Nano-engineering by MeV Ion Beams
Authors: Mishra Yogendra Kumar , Avasthi Devesh Kumar , Singh Fouran , Pivin Jean Claude , Pippel Eckhard 
Published: April 2011

AbstractThin silica films embedded with Au nanoparticles (NPs) were prepared by atom beam co-sputtering and RF-magnetron sputtering. The growth kinetics of Au NPs in atom beam co-sputtered film, under 90 MeV Ni ion irradiation, was studied by in-situ X ray diffraction experiment in the materials science beam line at IUAC, New Delhi. The growth of NPs from 4 nm (for pristine) to 9 nm at a fluence of 1 × 1014 ions/cm2 was observed with rapid growth upto the size track diameter, however slowed beyond it. 120 MeV Au ion irradiation of RF magnetron sputtered films resulted in the elongation of Au NPs along ion beam direction. The aspect ratio of elongated NPs (Au nanorods) is found to be ∼3.5, which mainly depends on the electronic energy deposited within the system. Hence the present work reports that the ion irradiation is an effective tool for tailoring the size, shape and size distribution of NPs. The results are discussed in the framework of thermal spike model.