bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long-Term Study on the Optical Performance of Ion Implanted PMMA Under the Influence of Different Media
Authors: Kallweit R. , Roll U. , Kuppe J. , Strack H. 
Published: April 2011

ABSTRACTTo be able to implement light-sensitive properties of ionimplanted PMMA in optical devices, it is first necessary to investigate the optical stability of the implanted layers. For this purpose, PMMA samples were implanted with nitrogen using doses from 7×1013/cm 2 to 5×1015/cm2 as well as energies from 100 keV to 380 keV. Subsequently these samples were exposed to dry media such as H2, 02, CO2, N2, Ar as well as to dry and humid atmosphere. In a further investigation, the optical stability was examined under the influence of different wavelength ranges. The changes resulting in these layers were ascertained over various periods (maximum of 5 years) by ellipsometric measurement of the refractive indices and, in parallel, the chemical modification of the surface was examined by means of XPS. If any changes were caused by the media, they consisted basically in a decrease of the index values and of the original concentrations on CH— and COH—groups generated by the bombardment— i.e. in a recombination of molecular chains. In correlation to the chemical modification of the surface, the refractive index partly changed drastically.
Adhesion Measurements of Thin Films by Several Methods
Authors: Kinbara Akira , Banno Tatsuya , Kondo Ichiharu , Takenaka Osamu 
Published: April 2011

ABSTRACTAdhesion of thin films to solid substrates has been measured by various methods. In addition to the traditional and the conventional methods, a novel method has been proposed. The adhesion is expressed by various units depending on the measuring method. Obtained values by typical or well known methods such as scratch, peel and pull method are expressed in terms of N, N/m and N/m2, respectively. Relation among these quantities was discussed. The interface structure between the films and the substrates was investigated by TEM, ED, EDS, etc. and was related to the adhesion. Particular attention was paid to the ion bombardment effect of the substrate on the adhesion.
Epitaxial Relationships of the a-Axis Oriented YBa2Cu3O7-x Thin Films on the PrBa2Cu3O7-xTx Buffered SrTiO3(100) by two Step PLD
Authors: Sung Gun Yong , Suh Jeong Dae , Nahm Sahn 
Published: April 2011

AbstractAn a-axis oriented YBa2Cu3O7-x (YBCO) thin film exhibiting zero resistance at 83 K and critical current density of 7.9x103 A/cm2 at 62 K was obtained on an 180 nm - thick PrBa2Cu3 O7-xx(PBCO) buffered SrTiO3(100) substrate by two step pulsed laser deposition (PLD). The volume fraction of a-axis orientation and the crystallinity(Xmin) of the 150 nm-thick YBCO thin films were increased with increasing the thickness of PBCO buffer layer, which was varied friom 0 nm to 180 nm. It is concluded that the thickness of PBCO buffer layer is one of the important parameters to control the structural and superconducting properties of the a-axis oriented YBCO thin films using the PBCO buffer layers.
Epitaxial LaNiO3Interlayers for Ferroelectric Memory Structures
Authors: Klein J. D. , Yen A. , Clauson S. L. 
Published: April 2011

AbstractLaNiO3 thin films were utilized as metallic contact layers in ferroelectric capacitors. The LaNiO3 films were probably epitaxial when deposited atop (100) LaAlO3 substrates. They exhibited metallic resistivity over a wide range of temperature and oxygen partial pressure. Subsequent deposition of PZT and LaNiO3 thin films atop LaNiO3/LaAlO3 allowed realization of parallel-plate ferroelectric capacitor structures. The suitability of such devices for nonvolatile memory applications was surveyed through pulsed voltage testing. The observed 1-second remanent polarization exceeded 18 μC/cm2. Long-term memory was demonstrated for up to sixteen hours. No decrease in remanent polarization was apparent after more than 109 switching cycles.
Thin Gate Oxide using a New RTO/-N Clusterable Reactor
Authors: Walk H. , Deutschmann L. , Martin F. , Masurel C. , Bauer A. 
Published: April 2011

ABSTRACTWe present recent results obtained in thin gate oxides. These oxides are grown in a new clusterable RTP-system for 200mm diameter wafers. The main innovations of the reactor are dealing with the chamber geometry, gas distribution, double pyrometry and dedicated circular lamp array in order to insure an optimized light flow onto the wafer. Analytical and electrical data are given according to several oxidant and nitridant ratios (O2, N2O), The influence of different process parameters such as temperature, reaction time, N-content are discussed.
Temperature Measurement of Metallized Silicon Wafers by Infrared Transmission Using Single- and Double-Pass Geometries
Authors: Cullen C.W. , Sturm J.C. 
Published: April 2011

ABSTRACTThe infrared transmission technique for the measurement of silicon wafer temperature has been extended to metallized wafers. For wafers with partial metal coverage, a single-pass method has been demonstrated from 200°C to 550°C. For wafers with blanket metal coverage, a novel double-pass infrared transmission technique is presented.
Silicon-Carbon Random Alloy Epitaxy on Silicon by Rapid Thermal Chemical Vapor Deposition
Authors: Mi J. , Letourneau P. , Ganière J.-D. , Gamhanou M. , Dutoit M. , Dubois C. , Dupuy J. C. 
Published: April 2011

ABSTRACTWe have grown dilute Si-C epitaxial layers on Si (100) substrates at 800°C with a RTCVD process using SiH4 and C3H8. C atoms can be kinetically stabilized in interstitial sites in the Si lattice at relatively high temperatures if process parameters, such as growth rate and C/Si flux ratio, are optimized.
Recrystallization of Amorphous Silicon Using Rapid Thermal Processing, Laser Annealing and Furnace Heating
Authors: Viatella J. , Singi R.K. , Thiakur R.P.S. , Sandhu G. , Harkness S.D. 
Published: April 2011

ABSTRACTRecrystallization of amorphous silicon has been investigated using conventional furnace annealing, incoherent light-based rapid thermal annealing (RTA) and pulsed laser annealing using excimner laser (wavelength=248 nm, energy density = 0.1−0.6 J/cm2) at a pulse width of approximately 20 nanoseconds. The effects of annealing methods are characterized for grain growth and crystallized orientation using transmission electron microscopy (TEM) and X-ray diffraction analysis. The various recrystallization methods are compared based on the structural properties of the resulting film and optimized thermal budgets for each heating mechanism are discussed.
A Comparison of In-Situ Vapor/Gas Phase Cleaning with Conventional RCA based Wet Cleaning
Authors: Grant John M. 
Published: April 2011

ABSTRACTA comparison study of the effectiveness of in-situ vapor/gas phase cleaning versus conventional wet RCA based cleaning has been performed. The effectiveness of the cleans were compared using Surface Photo-Voltage (SPV) measurements of the quality of a 70Å gate dielectric. Dielectrics grown in oxygen by Rapid Thermal Oxidation (RTO) were measured using SPV. The vapor/gas phase cleaning processes studied have three steps corresponding to the baths in a conventional RCA-based clean. A clean using O2 was used to clean the organic contaminants normally cleaned in the SC-1 bath, a C12 based step corresponded to the SC-2 solution, and an HF/alcohol etch was used to remove the oxide normally etched using buffered HF. It was seen that temperature control of the cleaning chamber walls is necessary to insure reproducible processes and reasonable pump down times. Measurements by SPV indicate that dielectrics grown after vapor-gas phase cleaning have lower interface trap densities than oxides grown after an RCA-based clean.
Shallow-Junction Formation by Rapid Thermal Diffusion into Silicon from Doped Spin-on Glass Films
Authors: Ventura L. , Slaoui A. , Hartiti B. , Muller J. C. , Stuck R. , Siffert P. 
Published: April 2011

ABSTRACTHere we investigate the possibility to use rapid thermal annealed spin-on doped glass (SOG) films as a doping source as well as a surface passivation layer. The dilution of the SOG liquid source with methanol allows to control the oxide film thickness and the dopant concentration. The results show that the combination of spin-on film (after dilution) and RTP can produce shallow lightly doped emitters. Junction depths less than 0.2 µm and surface concentrations in the range 1−20 × 1019 cm−3 are obtained. Sheet resistances lower than 150 Ω/□ are easily reached. Moreover, the minority-carrier diffusion length is improved due to the gettering effect induced by phosphorus diffusion. The use of the remaining SOG oxide film as a passivation layer makes this technique favourable for some application.
Modelling of Temperature Distribution of Semiconductors During Rapid Thermal Processing
Authors: Tillmann Andreas 
Published: April 2011

ABSTRACTThe modelling of temperature distribution on semiconductor wafers in common RTP-equipment is described. The incident intensity distribution on the wafer is calculated using raytracing. Based on this distribution the temperature distribution on the wafer is determined solving the two-dimensional heat conduction equation. If the dependence of a considered material property on the process temperature is known, the calculated temperature distribution can be convened to a distribution of this parameter.The distinctive feature of the described algorithms is the two-dimensional treatment of the distributions using a grid of ring segments, each with equal area. This grid is identical to the usual circular test patterns of multipoint measurement equipment. This is convenient since the evaluation of temperature uniformity in RTP equipment is done mostly by mapping an appropriate temperature dependent material property. All calculated distributions can be presented by contour plots as well as 3-D plots. This results in a very suitable method to compare simulated and experimental wafer maps.The agreement between simulated and experimental temperature distributions is shown.
Ab Initio Study of Pd Carbonyls and CO/Pd(110)
Authors: Ramprasad R. , Glassford K. M. , Adams J. B. 
Published: April 2011

AbstractWe have performed ab initio studies to understand the electronic and geometric aspects of the Pd-CO bond in small carbonyl clusters and the CO covered (2 × 1)p2mg superstructure of the Pd(110) surface. We have used the standard quantum chemistry package Gaussian to study the former system and an LDA formalism using ab initio pseudopotentials and a plane wave basis to study the latter. The latter results are preliminary; we intend to study thicker slabs in the future.
Aerosol Coating of Silica Fibers with Nanoparticles
Authors: Fotou George P. , Scott Steven J. , Pratsinis Sotiris E. 
Published: April 2011

AbstractUltrafine silica fibers were coated with nanosized particles by an aerosol process. The fibers were introduced in a diffusion flame reactor where silica particle formation took place by oxidation of SiCl4. Coagulation of particles with fibers resulted in fractal-like structures on the latter, enhancing the specific surface area of the product fibers. Ferrocene used as an additive at a mole fraction of 6.6 × 10−5 in the flame promoted the surface area enhancement. A sol-gel coating technique was also used to produce particle coated fibers.
Carbon Fiber Composite Molecular Sieves for Gas Separation
Authors: Jagtoyen M. , Derbyshire F. , Brubaker N. , Fel Y. Q. , Kimber G. , Matheny M. , Burchell T. 
Published: April 2011

IntroductionCarbon fibers are produced commercially from rayon, phenolics, polyacrylonitrile (PAN), or pitch. The last are further divided into fibers produced from isotropic pitch precursors, and those derived from pitch that has been pretreated to introduce a high concentration of carbonaceous mesophase. Over the past few decades, interest in research and manufacturing carbon fibers has overwhelmingly centered on producing fibers with high tensile strength and high modulus for lightweight, high performance composites, where polymers, metals, and carbon can form the continuous matrix. The fibers most commonly used in advanced materials are produced from PAN or mesophase pitch. Graphitized mesophase pitch fibers tend to have higher modulus and lower tensile strength than the PAN-based equivalents. They have advantages in applications requiring high stiffness, high electrical and thermal conductivity, low thermal expansion, and high temperature oxidation resistance, while PAN fibers are employed where high strength is required.
New Inorganic/Organic Copolymers (Ormocer®s) for
Dental Applications
Authors: Wolter Herbert , Storch Werner , Ott Heidrun 
Published: April 2011

ABSTRACTUrethane- and thioether (meth)acrylate alkoxysilanes have been used, as
sol-gel precursors, for the preparation of a special family of
inorganic/organic copolymers (ORMOCER®s). The basic silane type
offers the following structural and synthetic possibilities for modifying
the properties of the resulting copolymers: variation of the number of
alkoxy groups, combination with other, different, sol-gel precursors,
variation of the number of attached (meth)acrylate groups (1– 5), and
variation within the molecular segment (kind, structure and length)
connecting the inorganic with the organic polymer structure. To achieve the
additional organic polymer structure in the cured copolymer the use of
different radically induced polymerization approaches (UV-, visible light-,
thermal-and redox induced) is possible. Taking the incorporation of fillers
into account, the Young's modulus of these copolymers is adjustable in a
range of 1–17000 MPa, and the thermal expansion coefficient in a range of
17–250·10-6·K-1 (5 - 50 °C). Other advantages are
the low shrinkage (1 - 2,8 vol.-%), the high flexural strength (up to 160
MPa), and the high abrasion resistance. This new copolymer type seems to
have significant potential for medical applications, especially as dental
filling material to replace the currently used controversial amalgam
fillings.
Organic-Silica Hybrid Materials Consisting of the Double
Four-Ring Silicate Structure as a Building Block
Authors: Hasegawa Isao , Ishida Masanori , Motojima Seijl , Satokawa Shigeo 
Published: April 2011

ABSTRACTCopolymerization of the cubic octameric silicate anion
(Si8O208-) with dimethyldichlorosilane in 2, 2-dimethoxypropane has
yielded organic-silica hybrid materials consisting of the S13O20 structure
as a building block. The hybrid materials have shown high surface area by
calcination in air. The reaction conditions have been optimized to produce
the materials with higher specific surface area. As a result, the hybrid
materials with BET surface area of 406 m2 g-1 have
been obtained.
Sol-Gel Lithium Silicate Electrolyte Thin Films
Authors: Mouchon E. , Klein L. C. , Picard V. , Greenblatt M. 
Published: April 2011

ABSTRACTFor more than a decade, the sol-gel process has been used to prepare lithium
silicate gels that have potential applications as solid electrolytes in
lithium batteries and electrochromic windows. The interest in these
Li2O-SiC2 materials is their fast and stable ionic
conductivity from room temperature up to 350°C. Typically these materials
have been prepared with 15 mole % Li2O in bulk samples, but
rarely in thin films. This work was undertaken to prepare chemically stable
lithium silicate thin films with up to 30 mole % Li2O. Lithium
nitrate was used as the lithium precursor. Solutions were evaluated for
gelling time and homogeneity. Thin films were made by dip coating. After
heat treatment at 200, 250 and 300°C, films were characterized for surface
quality, thickness and microstructure using electron microscopy, x-ray
diffraction analysis and profilometry. Transparency was investigated in the
visible range (350–800 nm).
Photochemistry Channels of Merocyanine Encapsulated in Sol-Gel
Glasses
Authors: Mahloudji A. M. , Meuret L. B. , Lin C. T. 
Published: April 2011

ABSTRACTPhotophysical properties of l-Docosyl-4-(4-hydroxystyryl)pyridiniurn bromide
(SB), a merocyanine dye in solution and encapsulated in sol-gel derived
glass are investigated at 298 and 77 K. In solution, the absorption spectra
of SB display an equilibrium between the quinolinium and benzoid forms. The
equilibrium can be shifted to either quinolinium or benzoid form under an
acidic or basic condition, respectively. The emission spectra of SB, on the
other hand, give not only the quinolinium and benzoid forms but also the
quinoid form which emits at 500 nm. The existence of excited state quinoid
form of SB is also evident in the excitation spectrum while the emission at
500 nm is monitored. Both in solution and in xerogel, the quinoid form of SB
is shown to be photochemically unstable as compared to the benzoid form. It
is proposed that the photoexcited quinolinium form of SB is a proton
dissociative species which transforms readily to become the quinoid form.
The results indicate that photochemistry channels of SB are originated from
the quinoid form. Moreover, the benzoid form of SB (photochemically stable)
exhibits large hyperpolarizability due to its charge-transfer
characteristic, and is a desired molecular form for nonlinear optical (NLO)
applications. The material processing techniques for stabilizing the benzoid
form of SB in optically transparent sol-gel glasses are illustrated for the
first time.
Mixed-Metal Bismuth-Titanium Species. Chemical Routes to
Bi4Ti3O12
Authors: Papiernik Renee , Hubert-Pfalzgraf Liliane G. , Parola S. , Jagner S. , Soares-Carvalho F. , Thomas P. , Mercurio J.P. 
Published: April 2011

ABSTRACTSeveral routes to mixed-metal Bi-Ti species have been investigated. The
inertness of bismuth alkoxides Bi(OR)3 (R = Et, iPr) toward their
titanium analogs could be overcome by controlled microhydrolysis of Bi
alkoxides. The first mixed-metal species based on bismuth,
BiTi2O(OiPr)9, has thus been isolated and
structurally characterized.Coatings of Bi4Ti3O12 have been deposited
on silicon wafers by using the gels derived from Ti and Bi
2-methoxyethoxides solutions.
Fast Solution Precursor Synthesis of the 2223 Phase: the Role of
Lead in the Reaction Pathway
Authors: Miao H. , Primo V. , Ibáñez R. , Sapiña F. , Beltrán A. , Beltrán Uibcm D. 
Published: April 2011

ABSTRACTValuable mechanistic information, about the reaction pathway in the
formation of the 2223 phase, has been obtained by the use of a solution
synthesis route. The presence of lead in the starting mixture has remarkable
effects on the nature and stability of the different intermediates: i) the
grain size and morphology of Bi2CuO4 is severely
changed, ii) calcium carbonate is partially decomposed to yield the calcium
plumbate, iii) the 2201 phase results stabilized against the formation of
the collapsed phase
Bi17Sr16Cu7O49-δ, iv) the
melting point of the intermediate 2212 is lowered by about 10 °C. All these
effects, due to lead substitution, contribute to promote the formation of
the 2223 phase, controlling also the morphology and properties of the final
product.
Near-Net-Shape Forming of Celsian Ceramics from Ion-Exchanged
Zeolite Precursors
Authors: Hoghooghi Bahar , Mckittrick Joanna , Butler Chad , Helsel Eugene , Lopez Olivia 
Published: April 2011

ABSTRACTA technique has been developed for the synthesis and near-net-shape forming
of celsian glass-ceramics. This technique involves ion exchange of zeolite
precursor powders, heat treatment of the powders to temperatures between
800–90°C to form a glassy phase during which the samples are formed under
low stresses (<20 MPa). Upon further heat treatment to about 1000°C,
crystallization occurs and the amorphous formed body is transformed to the
celsian ceramic phase. Using this technique, and through the addition of
monoclinic seed particles as well as a mineralizer, monoclinic celsian was
produced at temperatures as low as 1000°C at heat treatment times of less
than one hour. This forming technique also resulted in a significant
reduction in the porosity of the ceramic bodies compared to free-sintered
samples.
Structural and Optical Aspects of Sol-Gel Optical
Composites
Authors: Li Xiaochun , King Terence A. 
Published: April 2011

ABSTRACTSol-gel derived optical composites have been prepared by both the
in-situ polymerisation and ORMOSIL methods and
characterised by FT-Raman and near infrared (NIR) spectroscopies regarding
their chemical structures, optical properties and molecular interactions. A
model based on intermolecular and intramolecular hydrogen bondings has been
proposed to interpret the observed spectral results.
Induction of Bidimensionality in CU-TI
Perovskttes
Authors: Palacín M.R. , Fuertes A. , Casañ-Pastor N. , Gómez-Romero P. 
Published: April 2011

ABSTRACTThe synteses and structure of the three-dimensional perovskite LajCuTiOg are
described. In this oxide Cu and Ti atoms are disordered among octahedral
sites. The introduction of oxygen vacancies by an adequate cation
substitution leads to the induction of bidimensionality as well as an
ordered arrangement of cations and oxygen vacancies as found in the layered
oxides
Ln2Ba2Cu2Ti2O11
(Ln=La,Nd,Eu).
Silica Porous Glasses With Silicon Impregnations
Authors: Roizin Yakov O. , Korlyakov Andrey B. , Gevelyuk Sergey A. 
Published: April 2011

ABSTRACTQuantum-size silicon enriched regions were formed in silica porous glasses
obtained by three different technologies. Processing in the spark discharge
and carbon reduction of silicon dioxide in the solid phase were performed
for this purpose. All fabricated specimens have been investigated in
relation to their electrical and photoluminescence (PL) properties. A
pronounced increase of visible luminescence and single-type changes in the
a.c. conductivity were registered in all cases.
Novel Inorganic Hydrogels Based on The Polymerization of
Cyanometalate Transition Metal Complexes With
[PdCl4]2-: A New Approach To Ceramic And Alloy
Precursors
Authors: Bocarsly Andrew B. , Kumar Gireesh , Heibel Marija 
Published: April 2011

ABSTRACTThe reaction of a wide variety of cyanometalate complexes of the general
form [M(CN)x]n- (where M= a transition metal ion) with
square planar [PdCl4]2- in aqueous solution leads to
the formation of linear polymers. Polymerization occurs via substitution of
chloride ligands on the Pd(II) centers, by the nitrogen end of the cyanide
ligand to generate extended bridging cyanide structures. Upon generation at
room temperature polymer solutions of this type under go a sol-gel
transition to generate robust hydrogels having water content in excess of
95%. In the case of the cyanocobaltate/tetrachloropalladate gel, pyrolysis
at 900°C produces ferromagnetic Pd/Co metallic alloys having novel
morphological character. Materials formed with a hydrogel having a 2:1 Pd to
Co stoichiometry are found to be “sponge-like”. When placed in water, the
metallic matrix swells becoming pliable and holding up to seven equivalents
of water per metal site. The conductivity and magnetic properties of this
material are maintained in the swollen state. Sintering of the Pd/Co
hydrogel in air generates the layered oxide, PbCoO2 having a
delafossite structure.