bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Efficiency Blue Organic Light Emitting Devices doped by BCzVBi in Hole and Electron Transport Layer
Authors: Kim Nam Ho , Kim You-Hyun , Yoon Ju-An , Lee Sang Youn , Yu Hyeong Hwa , Turak Ayse , Kim Woo Young 
Published: June 2019

ABSTRACTThe electroluminescent characteristics of blue organic light-emitting diodes(BOLEDs) were fabricated with single emitting layer using host-dopant system and doped charge carrier transport layers. The structure of the high efficiency BOLED device was; NPB(600Å)/NPB:BCzVBi-7%(100Å)/ADN:BCzVBi-7%(300Å)/BAlq:BCzVBi-7%(100Å)/BAlq(200Å)/Liq(20Å)/Al(1200Å) to optimize probability of exciton generation by doping BCzVBi in emitting layer and hole/electron transport layers(HTL/ETL) as well. Luminance and luminous efficiency of BOLED doped BCzVBi in EML and HTL/ETL improved from 10090 cd/m2 at 9.5V and 6.44 cd/A at 4.0V to 13190 cd/m2 at 9.5V and 7.64 cd/A at 4.0V about 30% and 18%, respectively, with CIE coordinates of (0.14, 0.17) comparing to BOLED doped BCzVBi in EML only
Oxidation of Single-Crystal γ′-Ni3A1 at Low Oxygen Partial Pressure
Authors: Schumann E. , Schnotz G. , Salzberger U. , Rühle M. 
Published: June 2019

ABSTRACTSingle crystals of γ′-Ni3Al((001)-oriented) were oxidized at 1223 K under an oxygen partial pressure of ∼4 ×10−19 atm for times ranging from 0.1 to 50 hours. Microstructural development of the oxide scale and subscale metal was studied by electron microscopy. A special technique permitted the reproducible and efficient preparation of TEM cross section specimens. Initially, a fine-grained γ-Al2O3 scale formed with a preferred orientation. Depletion of Al from the γ′-Ni3Al resultedin a Ni-Al solid solution zone between the oxide scale and the intermetallic. After 20 hours oxidation, a discontinuous α-A12O3 layer between the γ-A12O3 and the metal was observed. The α-A12O3 layer exhibited a much larger grain size than that of the γ-A12O3 and was continuous after 50 hours oxidation. Formation of the α-A12O3 layer correlated with a decreasing parabolic oxidation rate constant kp, as measured by thermogravimetric analysis (TGA).
The Microstructural Evolution of Nanometer Ruthenium Films in Ru/C Multilayers With Thermal Treatments
Authors: Nguyen Tai D. , Gronsky Ronald , Kortright Jeffrey B. 
Published: June 2019

AbstractThe evolution of nanometer Ru films sandwiched between various C layer thicknesses with thermal treatments was studied by plan-view and cross-sectional Transmission Electron Microscopy. Plan-view observation provides information on the Ru grain size, while crosssectional studies allow examination of the multilayer morphology. After annealing at 800°C for 30 minutes, the grain size in the 2 and 4 nm Ru layers show little difference from each other, while that in the I nm Ru layers depends strongly on the thickness of the C layers in the multilayers. It increases with decreasing C layer thickness. Agglomeration of the Ru layers is observed in Inmn Ru / 1nm C multilayers after annealing at 600°C for 30 minutes. The evolution of the microstructures and layered structure stability of the Ru/C system is compared to that of W/C and Ru/B4C systems.
Kinetics of Solid-State Reactions in Ni-Zr Thin Films
Authors: Schwarz R. B. , Rubin J. B. 
Published: June 2019

AbstractWe have studied the kinetics of the solid-state amorphizing reaction in thin film multilayers of Ni and Zr. Crystalline Ni and Zr films were deposited in ultra-high vacuum onto platinum resistance thermometers embedded in alumina. An electronic feedback circuit controls the temperature of the substrata by adjusting the power dissipated by the platinum resistors. We find that structural relaxation in the asdeposited Ni and Zr films affects the initial stages of the reaction. For long reaction times there is a discontinuous change in the reaction rate. The time to reach this transition increases with film thickness and depends exponentially on 1/T, with an apparent activation energy of 3 eV atom−1.
Heteroepitaxial Growth of MgO Films on NiO(100) Single Crystal Surfaces
Authors: Imaduddin S. , Davidson A.M. , Lad R.J. 
Published: June 2019

AbstractEpitaxial MgO layers were grown on cleaved NiO(100) single crystal surfaces. The less than 1% lattice mismatch between MgO and NiO allows almost ideal epitaxy of MgO at 100°C. The epitaxial films were created by dosing Mg onto stoichiometric NiO(100) both in ultra-high vacuum (UHV) and in an O2 atmosphere (5×10−7 Torr). Chemical interactions at the resulting interfaces were studied using XPS. When Mg is dosed onto NiO(100) in UHV, MgO forms by interacting with oxygen anions in the NiO substrate thereby reducing the nickel cations. Metallic Mg layers begin to form upon subsequent dosing. When Mg is deposited in O2, epitaxial MgO(100) layers grow to a thickness of at least 50Å as confirmed by in situ RHEED and LEED observations. Negligible intermixing between the MgO and NiO is observed during growth at 100°C and on subsequent annealing in UHV up to 600°C.
The Initial Stages of Metal Deposition on Metal and Semiconductor Electrodes Studied byIn SituStm
Authors: Kolb D. M. , Randler R. J. , Wielgosz R. I. , Ziegler J. C. 
Published: June 2019

ABSTRACTThe deposition of Cu onto Au(100) and of Pb onto n- Si(111) electrodes from aqueous solutions has been monitoredin situby scanning tunneling microscopy. In the first case, a bcc structure of the Cu overlayer is observed, which allows pseudomorphic growth on Au(100) up to the 10th layer. Then a slow structural transition to fee begins. In contrast, Pb on Si(111) is shown to deposit as 3D crystallites with flat (111) terminated surfaces.
In-Situ Characterization of the Surface State Density by Photoluminescence During Electrochemical Treatments of Silicon Surfaces
Authors: Dittrich T. , Timoshenko V. Y. , Rappich J. 
Published: June 2019

ABSTRACTThe photoluminescence (PL) of c-Si is probed stroboscopically with single pulses of a N2 laser during electrochemical treatments (hydrogenation and anodic oxidation). The PL intensity of indirect semiconductors such as Si is controlled by the non-radiative surface and bulk recombination. By this reason the density of surface states can be estimated for unknown surfaces by using a calibrated standard. The surface state density of a hydrogenated Si surface increases by exchanging the electrolyte by gaseous N2 or water.
Fabrication and Characterization of Nife Thin Film Composition Modulated Alloys
Authors: Leith S. D. , Schwartz D. T. 
Published: June 2019

ABSTRACTDescribed are results showing that an oscillating flow-field can induce spatially periodic composition variations in electrodeposited NiFe films. Flow-induced NiFe composition modulated alloys (CMA's) were deposited on the disk of a rotating disk electrode by oscillating the disk rotation rate during galvanostatic plating. Deposit composition and structure were investigated using potentiostatic stripping voltammetry and scanning probe microscopy. Results illustrate a linear relationship between the composition modulation wavelength and the flow oscillation period. CMA's with wavelengths less than 10 nm can be fabricated when plating with a disk rotation rate oscillation period less than 3 seconds.
Electrodeposition of High-Tc Superconductor Material for Microsensor Fabrication
Authors: Natarajan A. , Wang W. , Ma E. , Bhattacharya R. N. , Khan-Malek C. , Paranthaman M. , Martin P. M. 
Published: June 2019

ABSTRACTThin-films of YBa2Cu3O7 (YBCO) superconductor precursor were synthesized using an electrodeposition process. The YBCO precursor thin films were deposited on Ag foils using pulsed potential deposition conditions of 10 s at - 4 V and 10 s at -1 V (versus Ag reference electrode). The post-annealed films showed zero electrical resistance at 60 K. The procedures for the fabrication of a high precision micro-sensor using YBCO superconductor for measurement of weak magnetic fields are outlined. The micro-sensor templates were patterned using X-rays and precursor films were deposited into the features.
Electrochemical Study on the Growth of Multilayer Film Electrodes of the Conducting Polymers PPP, Pot and of the Copolymer of PPP and Pot
Authors: Kvarnström C. , Latonen R.-M. , Ivaska A. 
Published: June 2019

ABSTRACTMultilayer polymer film electrodes were prepared from the electrochemically synthesized conducting polymers poly(paraphenylene), PPP, poly(3-octylthiophene), POT and from the electrochemically synthesized copolymer of PPP and PO.T. The electrochemical behavior of the multilayer film electrodes made from PPP and POT is compared with the response of a copolymer layer. The structure of the copolymer film could be changed by varying the polymerization potential and the concentration as well as the ratio of the concentration of the two starting materials. Due to the slightly lower (0.15 V) oxidation potential of the POT monomer in comparison to the oxidation potential of biphenyl, POT is usually present to a higher extent than PPP in the electrochemically produced copolymer. The copolymer electrodes, the single polymer film layers and the multilayer polymer film electrodes showed different electrochemical response of the charging-discharging cycle.
Influence of Nucleation on the Crystallization Behavior of Electroless Nickel-Phosphorous Alloys
Authors: Oberie Robert 
Published: June 2019

AbstractThe production of amorphous electroless nickel (EN) deposits from hypophosphite (H2PO2−) containing solutions is well known. The crystallization of the deposits has been studied by differential scanning calorimetry (DSC) and the changes in crystallization behavior with deposit thickness have been attributed to chemical effects. In this work, DSC results from deposits initiated by use of a noble metal catalyst are compared to those from a conventional zincate.The implication of the DSC data is that the bulk structure of the EN deposit is determined to a large degree by the mechanism of deposit initiation. This is in contrast to the conventional view that solution chemistry is the dominant factor that determines the properties of the deposit.
Investigation of the Codeposition of Polymer Lattices With Copper on a Rotating Disk Electrode
Authors: Fransaer J. , Celis J. P. 
Published: June 2019

ABSTRACTThis article involves the study of the electrodeposition of composite coatings that form when colloidal particles deposit onto an electrode at which metal electrodeposition simultaneously occurs. The codeposition process of polystyrene (PS) and polymethylmethacrylate (PMMA) particles from a copper plating bath on a rotating disk electrode (rde) was investigated both theoretically and experimentally. The influence of the fluid flow velocity, density, mean size and zeta-potential of the particles, viscosity and temperature of the plating bath on the deposition rate of particles is studied using the theoretical model. The predictions of the model are compared with experimental results.
Etching of Polymers by Photo-Material Processing using an Excimer Lamp
Authors: Takezoe Noritaka , Yokotani Atsushi , Kurosawa Kou , Sasaki Wataru , Yoshida Kunio , Igarashi Tatsushi , Matsuno Hiromitsu 
Published: June 2019

ABSTRACTAn excimer lamp is a new light source which can produce shorter wavelength of vacuum ultraviolet radiation than conventional ArF excimer lasers. We have tried to use the excimer lamp for photo-etching of polymers such as polymethylmetacrylie and polyimidic resins. We have found that the etching process was including the chemical and the quantumn processes. We also applied this technique for etching of some single crystalline organic materials which were very important to opt-electronic applications.
High Resolution Displacement of Functional Groups onto Fluorocarbon Resin Surface by Using ArF Excimer Laser
Authors: Shimizu T. , Murahara M. 
Published: June 2019

ABSTRACTA Fluorocarbon resin surface was selectively modified by irradiation with a ArF laser beam through a thin layer of NaAlO2, B(OH)3, or H2O solution to give a hydrophilic property. As a result, with low fluence, the surface was most effectively modified with the NaAlO2 solution among the three solutions. However, the contact angle in this case changed by 10 degrees as the fluence changed only 1mJ/cm2. When modifying a large area of the surface, high resolution displacement could not be achieved because the laser beam was not uniform in displacing functional groups. Thus, the laser fluence was successfully made uniform by homogenizing the laser beam; the functional groups were replaced on the fluorocarbon resin surface with high resolution, which was successfully modified to be hydrophilic by distributing the laser fluence uniformly.
Oxygen Vacancy Migration in Disordered Gd2(ZrxTi1-x)2O7
Authors: Williford R.E. , Weber W.J. , Devanathan R. , Gale J.D. 
Published: June 2019

AbstractOxygen vacancy formation and migration energies in the pyrochlores Gd2(ZrxTi1-x)2O7 were computed using atomistic energy minimization methods, with particular attention to the role of cation antisite disorder. The interatomic potentials recognize oxygens in distinct crystallographic sites (polarizations) as distinct species, and permit assessment of the directional anisotropy in vacancy migration energies. Oxygen vacancy migration is determined by O48f - O48f transitions along the shortest edges of the TiO6 octahedra, in agreement with previous results. Oxygen vacancies migrate towards disorder to reduce local stresses. In contrast to previous work, the VO8a and VO8a + IO8b Frenkel defects are favored over the VO8f and VO48f + IO8b Frenkel. The transition VO8a -> VO48f is energetically favored for the ordered structure, and activates the three dimensional O48f - O48f vacancy migration network by filling empty 8a sites with 48f oxygens. Local regions of order and moderate disorder must both be present for optimum oxygen conductivity. High disorder retards vacancy migration.
Open Resonator Technique for Measurement of Thin Dielectric Film Properties on Optically Dense Substrates
Authors: Dudorov Sergey , Lioubtchenko Dmitri , Mallat Juha , Tuovinen Jussi , Räisänen Antti V. 
Published: June 2019

ABSTRACTThin dielectric films on the dielectric substrate are widely employed in millimeter and submillimeter wave device applications, so the problem of precise measurement of their properties is important. One of the most accurate technique for measurement of dielectric properties is the open resonator technique.In this work we propose the method for measurements of thin dielectric film properties on the dielectric substrate using the open semispherical resonator. A good agreement (within 1 %) was obtained in refractive index data between results obtained with direct measurements and with proposed method for thin layer of SI GaAs on a sapphire substrate.
Subsurface Damage Profile Characterization of Si Wafers with Uv/Millimeter-Wave Technique and Light Scattering Topography
Authors: Katoh Takeo , Kondo Hideyuki , Ogita Yoh-Ichiro , Kobayashi Ken-Ichi , Kurokawa Masaki 
Published: June 2019

ABSTRACTWe have characterized subsurface damage profiles of hydrogen-ion implanted silicon wafers by using a non-contact UV/Millimeter-Wave Technique and Light Scattering Topography (LST). A subsurface damage profile that was less than one micrometer was controlled by chemical mechanical polishing after hydrogen-ion implantation. On the area with the subsurface damage, the Photoconductivity Amplitude (PCA) signals measured by the UV/Millimeter-Wave Technique drastically weakened and the haze values measured by LST increased. A clear correlation has been found between the peak depth of the subsurface damage and the haze value. The spectral analyses of the surface images obtained by Atomic Force Microscopy (AFM) were carried out in order to separate the influences of surface micro roughness and subsurface damage on the haze value. The contribution of subsurface damage to the haze value can be formulated as the convolution of the damage profile and the transparency function of the incident laser in silicon crystal.
Isovalent Substitution of Sr for Ba in Ba3.75Nd9.5Ti18O54 Microwave Dielectric Ceramics – Experimental and Computer Modelling Studies
Authors: Setasuwon Paisan , Freer Robert , Azough Feridoon , Leach Colin 
Published: June 2019

ABSTRACTCeramics of Ba3.75Nd9.5Ti18O54 substituted with 2, 5, 10, 20 and 50% Sr have been prepared by the mixed oxide route. Specimens were sintered at temperatures in the range 1350–1500°C. Densities were ∼95% theoretical. The solubility limit for Sr replacing Ba was found to be ∼10%. The relative permittivity (∼80) was almost independent of Sr content, but 2% Sr increased the Qxf value to a maximum of 11000. Static simulation of Sr- bearing Ba3.75Nd9.5Ti18O54 successfully reproduced the structure and lattice parameters to within 1–2%. Different site distributions of Ba-Sr ions have been explored.
BWO-Characterization of Materials and Devices at Frequencies 100-1000 GHz.
Authors: Volkov A. A. , Anzin V. B. , Goncharov Yu. G. , Gorshunov B. P. , Komandin G. A. , Spector I. E. 
Published: June 2019

ABSTRACTWe have developed multipurpose spectral technique for amplitude and phase measurements at frequencies 100–1000 GHz based on the use of backward wave oscillators (BWOs) as sources of probing radiation. It utilizes to the utmost all the remarkable advantages of BWOs such as high radiation intensity, monochromaticity, polarization, as well as high speed and wide range of frequency tuning. Extremely simple and flexible open-space measurement geometries are used. The developed technique seems to be the most appropriate and promising for the reliable, precise and mass characterization of materials and devices at millimeter-submillimeter waves.
Hydrothermal Epitaxy of I:V Perovskite Thin Films
Authors: Goh Gregory K. L. , Donthu Suresh K. 
Published: June 2019

AbstractAlthough epitaxial II:IV perovskite films like BaTiO3 and Pb(Zr,Ti)O3 have been grown by the hydrothermal method, there are hardly any reports on the growth of I:V perovskite thin films by this low temperature technique. In this study, thin films of NaNbO3, KTaO3 and KNbO3 were grown on (100) oriented single crystal SrTiO3 substrates by the hydrothermal method at 200°C and below. X-ray diffraction (XRD) revealed that the as-synthesized films were epitaxial with one of their original cubic axes normal to the substrate (100) plane. Scanning electron microscopy (SEM) showed that the films formed by an island growth mechanism. KTaO3 was also used as a buffer layer in the growth of KNbO3 films in order to investigate the effect of lattice mismatch on surface morphology and epitaxial quality, as determined by SEM and XRD rocking curve measurements, respectively.
Orientation-Dependent Dielectric Anomalies in Relaxor-Based Crystal (PbMg1/3Nb2/3O3)0.68(PbTiO3)0.32 (PMN-32%PT)
Authors: Tu Chi-Shun , Schmidt V. Hugo 
Published: June 2019

AbstractDielectric permittivities and polarization-electric-field (P-E) hysteresis loops have been measured as a function of temperature in relaxor-based ferroelectric single crystals (PbMg1/3Nb2/3O3)0.68(PbTiO3)0.32 (PMN-32%PT) for <110>cub and <211>cub orientations. Contrary to the pure PbMg1/3Nb2/3O3 (PMN), PMN-32%PT exhibits apparent orientation dependences of dielectric permittivities, polarizations, and phase transitions. With a prior fieldcooled treatment, a field-induced state, perhaps of orthorhombic symmetry, is evidenced and coexists with the rhombohedral symmetry in the low-temperature region. This field-induced phase is manifested by an extra dielectric peak observed near 373 K for the <211>cub orientation.
Optical and Electrical Properties of Sol-Gel Processed Gd Doped Ferroelectric PLZT Thin Films
Authors: Thomas Reji , Mochizuki Shoich , Mihara Toshiyuki , Ishida Tadashi 
Published: June 2019

AbstractGadolinium(Gd) doped ferroelectric lead lanthanum zirconate titanate (PLGZT 6/2/65/35) thin films were prepared by sol-gel spin coating technique. Fused silica and platinized silicon were used as substrates. Two-step pre-annealing heat treatment was employed to prepare crack free films. Annealing temperature was optimized though the x-ray diffraction studies to prepare films in single perovskite phase. Effects of Pb concentration and the seeding layer on the crystallization were studied. Optical transmission spectra were recorded and from this, refractive index, extinction coefficient and thickness were calculated for amorphous films on fused silica annealed at 400°C. In addition, the resultant films showed more than 60% transmission in the visible region. The electrical measurements were conducted on metal-ferroelectric-metal (MFM) capacitors. Ferroelectric properties of crystalline films were studied by plotting the P-E hysteresis loop.
Oxygen Vacancies in Perovskite and Related Structures: Implications for the Lower Mantle
Authors: McCammon Catherine A. , Becerro Ana Isabel , Lauterbach Stefan , Bläß Ulrich , Marion Stefan , Langenhorst Falko , Angel Ross J. , Aken Peter van , Seifert Friedrich 
Published: June 2019

AbstractThe oxygen vacancy ordering process and displacive transitions have been characterised in the system CaTiO3-CaFeO2.5 as a function of composition and temperature at atmospheric pressure using X-ray diffraction, Mössbauer spectroscopy, infrared spectroscopy, transmission electron microscopy, electron energy loss spectroscopy, neutron diffraction and electrical conductivity methods. With increasing concentration of vacancies the following sequence is observed: isolated defects → short defect chains → infinite chains in layers. Similar experiments at high pressures and temperatures have been conducted to determine the nature of oxygen vacancies in the lower mantle phases (Mg,Fe)(Si,Al)O3-σ and Ca(Si,Fe)O3-σ perovskite.
Characterization of Sol Gel Prepared KTN Thin Films and Powders by Raman, XRD, and Thermal Analysis Techniques.
Authors: Savvinov A.A. , Majumder S.B. , Katiyar R.S. 
Published: June 2019

AbstractThe renewed interest in KTa1-xNbxO (KTN) mixed perovskite materials is connected with their remarkable dielectric properties in the dilute compositions. KTN thin films with x = 0.35 have been prepared on different substrates by sol-gel technique as well as a set of powders with x = 0, 0.05, 0.1, 0.25, 0.48, 0.65, 0.75, and 1. Properties of the material change drastically with the change of x, because of relaxation of both translational and inversion symmetry due to a static disorder in the Nb distribution and the dynamic effect of a precursor ferroelectric order above Tc. Special attention was paid to the characteristic feature of coupling of the single-phonon state to a two-acoustic-phonon feature through anharmonic terms in the potential function as well as behavior of the TO3 mode which becomes a narrow peak of the first-order scattering in the tetragonal ferroelectric phase and shows a tendency to split below Tc2 in the orthorhombic phase. The wide range of x allows better understanding of dynamic processes in the KTN bulk materials which in turn helps in the studies of thin films. The above mentioned materials were studied using Raman scattering, XRD, and thermal analysis techniques.