Sintering behavior and thermal expansion properties of the solid solution series Nd2-xCexCuO4±δ (0 ≤ x ≤ 0.20) have been investigated over the temperature range of 298 to 1100 K. Significant anisotropy in the lattice expansion coefficient in the a/b and c crystallographic axes was noted on increasing Ce content, which is consistent with the tetragonal unit cell. The lattice expansion in the c axis was found to decrease on increasing temperature for compositions up to x = 0.10, which is likely to be from variations in the oxygen stoichiometry. A variation in the sintering behavior was also noted on varying Ce content, with the onset of sintering temperature reaching a maximum at x = 0.10. A secondary sintering stage was noted for compositions with x > 0.10. Associated with the introduction of a secondary stage on sintering is an overall increase in the temperature at which the sintering is at a maximum.

Hydrophobic-hydrophilic patterns were formed on indium tin oxide substrates, and thick films of poly(phenylsilsesquioxane) (PhSiO3/2) particles, prepared by the sol-gel process, were selectively deposited onto hydrophilic areas of the substrates by electrophoresis. The films composed of PhSiO3/2 particles became transparent with morphological changes from aggregates of particles to a continuous phase after a heat treatment. After heat treatment at 200 °C, convex-shaped PhSiO3/2 micropatterns were formed on the hydrophilic region of the pattern. Moreover, the height of micropatterns was controlled by the deposition time. This patterning technique has a wide variety of applications such as fabrication of micro-optical components.

Single-crystal lead titanate [(001)PbTiO3 (PT)] thin films were heteroepitaxially grown on a miscut strontium titanate [(001)SrTiO3 (ST)] substrate by radio frequency magnetron sputtering. The PT thin films were grown via a step-flow growth. The step-flow growth enhanced the layer growth resulting in the continuous (001) single-crystal structure without a dislocated interface for the film thickness below 200 to 250 nm. The PT thin films show a small temperature variation of the lattice parameters unlikely to the bulk PT crystals due to the substrate clamping. The temperature variation of the lattice constants is discussed in terms of the thermo-elastic deformation analysis for the PT/ST heterostructure.

Carbon nanotubes (CNTs) were grown on micron-sized Al2O3 particles in an atmosphere of methane and hydrogen at 700 °C under the catalysis of Fe–Ni nanoparticles that had been deposited on the surface of Al2O3 particles by an electroless plating technique. The individual and competitive adsorption capacities of Pb2+, Cu2+, and Cd2+ from aqueous solution by CNTs on Al2O3 particles were studied. The results showed that the adsorption behavior of these metal ions by as-grown CNTs on Al2O3 particles is in good agreement with the Langmuir adsorption model. The maximum individual adsorption capacities of Pb2+, Cu2+, and Cd2+ from water by as-grown CNTs on Al2O3 particles are 62.50, 27.03, and 9.30 mg/g, respectively. The CNTs on Al2O3 particles have promising potential applications in removing soluble heavy metals from aqueous solutions.

A novel cyclotriphosphazene-based low-molecular weight organogelator was prepared by immobilization of six dialkylated L-glutamide derivatives on a cyclotriphosphazene core, and its ability as a self-assembling organogelator was investigated. The organogelator exhibited enhanced gelation ability and chirality, and thixotropic property for self-restoring to a gel state; this was compared to the corresponding L-glutamide-derived organogelator without the core. The gelation test, transmission electron microscopy observation, and circular dichroism (CD) spectral study showed that the gelation and aggregation ability were enhanced by immobilization onto the cyclotriphosphazene core. Gels in chloroform and cyclohexane-ethanol (95:5) mixture showed an unusual thixotropic property.

An amorphous nanoparticulate aluminosilicate 3/2-mullite precursor has been synthesized and carefully characterized. The sol contained 2-nm particles of Q3(3Al) silica species together with six-coordinated alumina, which suggested an allophane-like structure of the nanoparticles. The sol remained stable for years, and formed an easily redispersible physical gel upon solvent evaporation. The gel crystallized to mullite at temperatures below 1000 °C, without going through any intermediate spinel phase. Thus, the nanoparticulate precursor is regarded as a homogeneous high-purity mullite precursor with a high Si–O–Al bond density, which is useful in the preparation of various nanostructured Al-rich aluminosilicate materials. The sols and gels were characterized by small-angle x-ray scattering, dynamic light scattering, x-ray diffraction, 27Al and 29Si magic-angle spinning (MAS) nuclear magnetic resonance spectroscopy, and differential thermal analysis.

New curable organic-inorganic hybrid materials with a low internal optical attenuation of <0.35 dB/cm at the telecommunication wavelength and high thermal stability (∼370 °C) were synthesized by a nonhydrolytic reaction using vinyltriiospropenoxysilane (VTIPS) and diphenylsilanediol (DPSD) in which alcohol condensation takes place without hydrolysis of the starting materials. The molecular structure and the reaction mechanism of the synthesized organic-inorganic hybrid materials were investigated. The nonhydrolytic reaction of VTIPS and DPSD represented a high degree of condensation, and the molecules of the organic-inorganic hybrid materials exhibited the structure of an oligosiloxane modified with diphenyl, vinyl, and isopropenoxy. These organic-inorganic hybrid materials cured by polymerization of vinyl and isopropenoxy groups can be promising candidates for optical applications due to their good optical and thermal properties in addition to the availability of soft-lithography.

Partial and integral enthalpies of mixing of liquid Ag–Ni and Ag–Ni–Sn alloys were determined at different temperatures, i.e., at 1500 °C for binary Ag–Ni alloys and at 1000, 1220, and 1400 °C for ternary Ag–Ni–Sn alloys. Two different Calvet-type micro-calorimeters were used for the measurements employing drop calorimetry techniques. The binary data were evaluated by means of a standard Redlich–Kister polynomial fit whereas ternary data were fitted on the basis of an extended Redlich–Kister–Muggianu model for substitutional solutions. No significant temperature dependence could be detected for the ternary enthalpies of mixing. From the experimental ternary data, it was possible to deduce the liquidus isotherm at 1000 °C as well as the extension of the liquid miscibility gap at 1220 and 1400 °C.

A highly deformable Zr–Al–Cu–Ni–Sn alloy system without any catastrophic failure has been developed and the underling mechanism for exceptional plasticity has been investigated in terms of structural characteristics and atomic movement kinetics. The as-cast Zr61.7Al8Ni13Cu17Sn0.3 bulk metallic glass has many local nanoscale ordering features. They can play a critical role in nucleating abundant shear bands that sufficiently accommodate global plasticity. During deformation at room temperature, the ordered regions do not grow, providing a structural stability, possibly from the sluggish atomic movement kinetics. Thermal activation energy for crystallization of the Zr61.7Al8Ni13Cu17Sn0.3 alloy is estimated as 3.96 eV, which is about 2.8 times higher than that of the Z41.2Ti13.8Cu12.5Ni10Be22.5 alloy [Vitreloy 1 (Vit1)] and the dynamic mass flow rate is around 10 times slower than that of Vit1. A thermomechanical estimation of compressive strain rates under constant stress shows a sluggish atomic movement upon the addition of Sn.

TiO2 nanoparticles with embedded magnetite were suspended in aqueous HAuCl4 and ultraviolet irradiated to photodeposit gold on the surface. The degree of gold coating and the wavelength of absorbance could be controlled by adjusting [HAuCl4]. Absorbance maxima were between 540-590 nm. Particles exhibited superparamagnetic properties (blocking temperature ∼170 K) whether or not coated with gold. These particles have potential applications as drug delivery agents, magnetic imaging contrast agents, and magnetically separatable photocatalysts with unique surface properties.

An expanding cavity model (ECM) for determining indentation hardness of elastic–strain-hardening plastic materials is developed. The derivation is based on a strain gradient plasticity solution for an internally pressurized thick-walled spherical shell of an elastic linear-hardening material. Closed-form formulas are provided for both conical and spherical indentations. The formulas explicitly show that indentation hardness depends on Young's modulus, yield stress, strain-hardening index, and strain gradient coefficient of the indented material as well as on the geometry of the indenter. The newly formulated ECM can capture the indentation size effect, unlike classical plasticity based ECMs. The new model reduces to existing classical plasticity based ECMs (including Johnson's ECM for elastic-perfectly plastic materials) when the strain gradient effect is not considered. The presently developed ECM is validated by comparing with existing experimental hardness data. The numerical results obtained using the new model reveal that the hardness is indeed indentation size dependent when the indentation radius is very small: the smaller the indentation, the larger the hardness. Also, the indentation hardness is seen to increase with the Young's modulus and strain-hardening level of the indented material for both conical and spherical indentations. The strain-hardening effect on the hardness is observed to be significant for materials having strong strain-hardening characteristics. In addition, it is found that the indentation hardness increases with decreasing cone angle of the conical indenter or decreasing radius of the spherical indenter. These trends agree with existing experimental observations and model predictions.

We experimentally investigated the pressure-induced infiltration of a nanoporous silica-based energy absorption system modified by polyacrylic acid partial sodium salt (sodium polyacrylate). Under ambient conditions, sodium polyacrylate forms a soft matter with water. As the hydrostatic pressure increases, the dehydration of the soft matter occurs and the nanopores are filled by water molecules, accompanied by a significant energy dissipation. This result has fundamental scientific interest for understanding behaviors of confined liquids and great technological importance for developing advanced solid-like protective/damping materials.

To investigate the effect of plasma-incorporated fluorine on Si donors in pseudomorphic-high electron mobility transistors (P-HEMTs), we used x-ray photoemission spectroscopy to analyze three layers near the Si δ-doped layer and the Si δ-doped layer itself, in which we previously found fluorine accumulation after post-thermal annealing following fluorocarbon-based plasma exposure. For this evaluation, we developed controllable and low-speed AlGaAs wet-chemical etching using citric-acid-based wet etchant. We used it to expose one of the layers to be analyzed: one 7.5 nm above the Si δ-doped layer, one 1.5 nm above it, the δ-doped layer itself, and one 1.5 nm below it. We found that the accumulated fluorine localized in the δ-doped layer and reacted with Si donors. This is apparently the main reason for the carrier passivation in the fluorocarbon-based plasma-exposed P-HEMTs.

A CoFe2O4 particle/organic hybrid was synthesized using in situ processing of metalorganics of cobalt and iron below 100 °C. A mixture of cobalt (II) acetylacetonate (CA) and iron (III) 3-allylacetylacetonate (IAA) was hydrolyzed and polymerized yielding cobalt ferrite particle/organic hybrid. The crystallinity of cobalt ferrite depended upon the hydrolysis conditions of cobalt acetylacetonate-iron 3-allylacetylacetonate (CA-IAA). Nanocrystalline cobalt ferrite particles were uniformly dispersed in the organic matrix. The saturation magnetization of hybrid increased with increasing crystallinity of cobalt ferrite particles in the organic matrix. The hybrid showed a magnetization-applied field (BH) curve with no coercive force at room temperature. The magnetization versus H/T curves from 150 to 300 K were superimposed on the same curve and satisfied the Langevin equation. The hybrid revealed a saturation magnetization of 33.7 emu/g and a coercivity of 11 kOe at 4.2 K.