Yafei Zhang、Zhonghua Zhou、Hu‐Lin Li1996-01-29Applied Physics Letters
Crystalline carbon nitride films have been synthesized in a rf plasma assisted hot filament chemical vapor deposition system. Large crystalline grains up to ∼10 μm in size as well as film-like regions are observed in the morphology of the films. β-C3N4 with two groups of lattice parameters (one is consistent with the…
Metal and Thin Film MechanicsSemiconductor materials and devicesDiamond and Carbon-based Materials Research
Tingkai Li、Yongfei Zhu、Seshu B. Desu 等 5 位作者1996-01-29Applied Physics Letters
Ferroelectric layered-oxides SrBi2Ta2O9 thin films were prepared on Pt coated Si wafers and single-crystal sapphire by metalorganic chemical vapor deposition (MOCVD). The films were specular and crack-free and showed complete crystallization at temperatures between 650 and 700 °C. Good ferroelectric properties were ob…
Ferroelectric and Piezoelectric MaterialsSemiconductor materials and devicesAcoustic Wave Resonator Technologies
Husam N. Alshareef、D. Dimos、T. J. Boyle 等 5 位作者1996-01-29Applied Physics Letters
SrBi2Ta2O9 (SBT) thin films are known to exhibit no polarization fatigue with electric field cycling. However, we have discovered that optical illumination combined with a bias voltage near the switching threshold can result in significant (≳90%) suppression of the switchable polarization of SBT thin film capacitors.…
Ferroelectric and Piezoelectric MaterialsSemiconductor materials and devicesDielectric materials and actuators
Ming Lü、A. Bousetta、A. Bensaoula 等 5 位作者1996-01-29Applied Physics Letters
Boron nitride (BN) thin films (containing mixed cBN/hBN phase) have been deposited on Si(100) substrates using neutralized nitrogen beam and electron beam evaporation of boron. All as-deposited BN films were p type with a room-temperature carrier concentration in the range of 5×1016 to 1×1017 cm−3. The Mg-doped BN fil…
Metal and Thin Film MechanicsDiamond and Carbon-based Materials ResearchBoron and Carbon Nanomaterials Research
Y. Suzuki、R. B. van Dover、E. M. Gyorgy 等 11 位作者1996-01-29Applied Physics Letters
We have grown epitaxial spinel ferrite thin films of (Mn,Zn) Fe2O4 and CoFe2O4 on (100) and (110) SrTiO3 and MgAl2O4 buffered by spinel structure buffer layers. High quality spinel ferrite films were grown at 400 °C on buffer layers that were grown at 600 °C and postannealed at 1000 °C. Although (Mn,Zn) Fe2O4 grown di…
Multiferroics and related materialsMagnetic Properties and Synthesis of FerritesMagnetic Properties and Applications
M. J. Mehl、L. L. Boyer、H. T. Stokes1996-01-29arXiv
This is a brief description of how to derive the local ``atomic'' potentials from the Self-Consistent Atomic Deformation (SCAD) model density function. Particular attention is paid to the spherically averaged case.
Materials Sciencemtrl-th
Hajime Tanaka1996-01-29Physical Review Letters
We demonstrate here the possibility that strong dynamic asymmetry between two components of a fluid mixture generally leads to unusual phase separation (``viscoelastic phase separation''), which does not belong to the conventional classification of phase separation. In addition to polymer solutions, a mixture, one of…
Liquid Crystal Research AdvancementsMaterial Dynamics and PropertiesBlock Copolymer Self-Assembly
Robert M. Grotzfeld、Neil R. Branda、Julius Rebek1996-01-26Science
Here, the synthesis of a bowl-shaped molecule is described and evidence of its reversible dimerization by means of hydrogen bonds is presented. The dimer features a flattened spherical cavity of peculiar symmetry and acts as a host for the encapsulation of guest molecules of complementary shape. Encapsulation of aroma…
Polymer composites and self-healingSupramolecular Self-Assembly in MaterialsDendrimers and Hyperbranched Polymers
Jonathan P. K. Doye、David J. Wales1996-01-26Science
Insights into the structure of simple liquids are presented from analysis of the effect of the range of interatomic forces on the multidimensional potential energy surfaces of bulk material and clusters. An understanding at the microscopic level is provided of how the liquid phase is destabilized in systems with very…
High-pressure geophysics and materialsMaterial Dynamics and PropertiesChemical Thermodynamics and Molecular Structure
Daniel Anderson、M. Grae Worster1996-01-25Journal of Fluid Mechanics
We consider the solidification of a binary alloy in a mushy layer and analyse the linear stability of a quiescent state with specific interest in identifying an oscillatory convective instability. We employ a near-eutectic approximation and consider the limit of large far-field temperature. These asymptotic limits all…
Solidification and crystal growth phenomenaFluid Dynamics and Thin Filmsnanoparticles nucleation surface interactions
Xiaofan Li、C. Pozrikidis1996-01-25Journal of Fluid Mechanics
The hydrostatic shape, transient deformation, and asymptotic shape of a small liquid drop with uniform surface tension adhering to a planar wall subject to an overpassing simple shear flow are studied under conditions of Stokes flow. The effects of gravity are considered to be negligible, and the contact line is assum…
Surface Modification and SuperhydrophobicityFluid Dynamics and Heat TransferFluid Dynamics and Thin Films
Yeong‐Tarng Shieh、Jan‐Hon Su、Gurusamy Manivannan 等 6 位作者1996-01-24Journal of Applied Polymer Science
Supercritical fluid (SCF) technology involving carbon dioxide is recently receiving wide attention due to its vast potential application in various fields such as cleaning, extraction, synthesis, etc., in addition to its environmental benefits. To fully exploit the use of SCFs in new technologies, it is important to u…
Carbon Nanotubes in CompositesPhase Equilibria and ThermodynamicsPolymer Foaming and Composites
Yeong‐Tarng Shieh、Jan‐Hon Su、Gurusamy Manivannan 等 6 位作者1996-01-24Journal of Applied Polymer Science
In continuation of our goal to implement supercritical fluid (SCF) technology for various applications such as precision cleaning, foaming, and impregnation of materials, a systematic study has been performed involving amorphous polymers. Eleven different polymers of amorphous nature have been subjected to supercritic…
Phase Equilibria and ThermodynamicsCarbon dioxide utilization in catalysisPolymer Foaming and Composites
Gabriel J. Osanaiye1996-01-24Journal of Applied Polymer Science
The effects of carbon black loadings ℓ, Temperature T, and shear frequency ω on dynamic mechanical properties of EPDM gum elastomer and its carbon black compounds were investigated under sinusoidal shear flows. The regions of shear flows where the gum elastomer and its carbon black compounds exhibited characteristic p…
Polymer Nanocomposites and PropertiesPolymer composites and self-healingDielectric materials and actuators
Meital Zilberman、A. Siegmann、M. Narkis1996-01-24Journal of Applied Polymer Science
The amorphous phase of a series of random 6/6.9 copolyamides was investigated. It was characterized by the glass transition temperature (Tg) and the hydrogen bond content, as a function of the copolymer composition, compared to the corresponding homopolymers, polyamide 6 and polyamide 6.9. The hydrogen bonds in the am…
Polymer crystallization and propertiesPolymer Nanocomposites and PropertiesSynthesis and properties of polymers
B. E. Tiganis、Robert A. Shanks、Yu Long1996-01-24Journal of Applied Polymer Science
Polypropylene (PP) was extruded and injection-molded several times to mimic the effect of recycling procedures on PP. Differential scanning calorimetry (DSC) was used to follow crystallization rates under isothermal conditions in a temperature range of 120–150°C. Melting behavior and equilibrium melting temperatures w…
Polymer crystallization and propertiesbiodegradable polymer synthesis and propertiesMicroplastics and Plastic Pollution
B. E. Tiganis、Robert A. Shanks、Yu Long1996-01-24Journal of Applied Polymer Science
Polypropylene (PP) was extruded and injection-molded several times to mimic the effect of recycling procedures on PP. Differential scanning calorimetry (DSC) was used to follow crystallization rates under isothermal conditions in a temperature range of 120–150°C. Melting behavior and equilibrium melting temperatures w…
Polymer crystallization and propertiesbiodegradable polymer synthesis and propertiesMicroplastics and Plastic Pollution
Meltem �el k、Mehmet Sa�ak1996-01-24Journal of Applied Polymer Science
The chemical grafting of acrylamide-methacrylic acid (AAM-MAA) mixture onto poly(ethylene terephthalate) (PET) fibers using azobisisobutyronitrile as a chemical initiator was investigated. The use of MAA as a comonomer increased the amount of AAM introduced to the PET fiber up to 33.0%, while the grafting of AAM onto…
Advanced Cellulose Research StudiesMicroplastics and Plastic PollutionTextile materials and evaluations
D. Likhatchev、C. Gutierrez‐Wing、I. E. Kardash 等 4 位作者1996-01-24Journal of Applied Polymer Science
Aromatic polyimides were synthesized from 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (6F-OH diamine) and different aromatic dianhydrides by a one-step hightemperature polycondensation, or by a two-step procedure using either thermal or chemical imidization of poly(amic acids), PAA. The obtained polyimides were…
Synthetic Organic Chemistry MethodsSynthesis and properties of polymersSilicone and Siloxane Chemistry
M. D. Migahed、Nabeel A. Bakr、Mahmoud Abdelhamid 等 5 位作者1996-01-24Journal of Applied Polymer Science
The ultraviolet spectra of pure and lead salt-poly(vinyl alcohol) (PVA) composite films were studied at room temperature. Blending of PVA with lead acetate and lead nitrate cause a considerable change in the UV spectrum, indicating electronic structure modifications. The complex permittivity (ϵ*) and the complex elect…
Conducting polymers and applicationsDielectric materials and actuatorsPolymer Nanocomposite Synthesis and Irradiation