A novel multiferroic thin-film heterostructure exhibiting both ferromagnetic (FM) and ferroelectric (FE) properties, as well as magneto-optic (MO) and electro-optic (EO) properties, was fabricated via a wet chemical route. Oxide buffer layers were used to allow the growth of ferroelectric lanthanum modified lead magnesium niobate titanate (La:PMNT) layer on top of ferromagnetic bismuth and aluminum substituted yttrium iron garnet (BiAl:YIG). X-ray diffractometer (XRD) analysis confirmed the formation of both crystalline structures. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to examine the surface and cross-section morphologies of the resulted heterostructure. Multiferroic properties of the film were investigated.

A hierarchical computational method has been developed and used with a finite-element microstructurally based dislocation density multiple-slip crystalline formulation to predict how nanoindentation affects behavior in face-centered cubic crystalline aggregates at scales that span the molecular to the continuum level. Displacement profiles from molecular dynamics simulations of nanoindentation were used to obtain scaling relations, which are based on indented depths, grain-sizes, and grain aggregate distributions. These scaling relations are then used to coarsen grains in a microstructurally based finite-element formulation that accounts for dislocation density evolution, crystalline structures, and grain-sizes. This computational approach was validated with a number of experimental measurements pertaining to single gold crystals. This hierarchical model provides a methodology to link molecular level simulations with a microstructurally based finite element method formulation that can be used to ascertain inelastic effects, such as shear-slip distribution, pressure accumulation, and dislocation density and slip-rate evolution at physical scales that are commensurate with ductile behavior at the microstructural scale.

A novel stearic acid (SA)/3-aminopropyltrethoxysilane (APS) composite structure was fabricated using the combined method of the Langmuir–Blodgett technique and self-assembly monolayer (SAM) technique. Its frictional, adhesive properties and interface contact types between the atomic force microscope tip and the samples were evaluated based on Amonton’s laws and the general Carpick’s transition equation, respectively. The results showed that the tip–sample contacts corresponded to the Johnson–Kendall–Robert/Derjaguin–Muller–Toporov (DMT) transition model for SiO2, APS-SAMs, and the unheated SA-APS composite structure, and for the heated SA-APS bilayer to the DMT model. Frictional forces for the four samples were linearly dependent on external loads at higher loads, and at lower loads they were significantly affected by adhesive forces. Frictional and scratching tests showed that the heated SA-APS composite structure exhibited the best lubricating properties and adhesion resistance ability, and its wear resistance capacity was greatly improved due to the binding-mode conversion from hydrogen bonds to covalent bonds. Thus, this kind of composite bilayer might be promising for applications in the lubrication of nano/microelectromechanical systems.

Millimetric spherical beads of a biocompatible composite were produced from sodium alginate, a natural polysaccharide, and nanostructured hydroxyapatite (HA). It was shown that the composite was effective in the removal of lead ions and lead phosphate nanoparticles from high-contaminated simulated gastric fluid. X-ray diffraction spectroscopy and scanning electron microscopy analyses performed on HA–alginate beads after the Pb2+ uptake showed that nanocrystals of a lead phosphate, [Pb10–xCax(PO4)6Cl2], were precipitated on the bead surface. The cross-linked polymer chain had a double role: (i) keep Pb2+ ions and lead phosphate nanoparticles bounded to the bead surface, preventing their bioavailability in stomach fluid; and (ii) delay HA dissolution in the acidic conditions of the stomach, assuring that an excess of Ca2+ will not be released to simulated gastric fluid. Desorption experiments in simulated enteric fluid revealed that lead remained immobilized in the calcium phosphate phase in the intestinal tract. These results indicate HA–alginate composite as a potential system for heavy metals removal from contaminated gastric and enteric human fluids, minimizing its adsorption by the human body.

The mechanical properties of a new Fe41Co7Cr15Mo14Y2C15B6 bulk glassy alloy were studied by impact bending, compression, and hardness tests carried out at room temperature. The compressive fracture strength, elastic strain to fracture, Young’s modulus and Vickers hardness were measured to be 3.5 GPa, 1.5%, 265 GPa, and 1253 kg mm−2, respectively. The fracture mode of the glassy alloy under uniaxial compression is different from those of other bulk metallic glasses in that this fracture mode causes the samples to be broken, in an exploding manner, into a large number of micrometer-scale pieces. The fracture mechanisms of this bulk glassy alloy under bending and uniaxial compression are discussed based on the observation of the fracture surfaces. Vickers indentation tests indicate that the structure of the glassy ingot may be inhomogeneous.

Silver nanoparticles were synthesized by an inert gas condensation method using flowing helium in the process chamber. Nucleation, growth mechanism, and the kinetics of nanoparticle formation in vapor phase are studied. Effect of process parameters, such as evaporation temperature and inert gas pressure, on the particle crystallinity, morphology, and size distribution are examined. Particles were synthesized at evaporation temperatures of 1123, 1273, and 1423 K and at helium pressures of 0.5, 1, 5, 50, and 100 Torr. Synthesized silver nanoparticles were characterized by x-ray diffraction (XRD) and transmission electron microscopy (TEM). The particle size ranged from 9 to 32 nm, depending on the growth conditions. At lower evaporation temperature and inert gas pressure, smaller particles with spherical shape showing less agglomeration are formed. Based on the experimental results and theoretical model of surface free energy and undercooling as a function of evaporation temperature and inert gas pressure, particle formation is analyzed. A simple operating map for nanoparticle synthesis is presented. The theoretical model is well supported by the experimental data.

The nature of magnetoelectric (ME) interactions has been investigated in lead zirconate titanate (PZT) and (111) or (110) single-crystal nickel zinc ferrites. Data on the dependence of low-frequency ME voltage coefficients on static magnetic field orientation show (i) highest ME coefficients for bias field H along [100] and the smallest for H parallel to [110] and (ii) strongest ME interactions for transverse fields and for samples with Zn concentration of 0.3. Measurements on frequency dependence of ME coefficients reveal resonance enhancement due to bending and radial acoustic modes. The highest voltage coefficient is measured for radial modes in a sample with Zn concentration of 0.2. Theoretical estimates of low-frequency and resonance ME parameters are in very good agreement with data.

ZnS:Mn cubes, microspheres, and nanospheres were prepared by the solvothermal synthesis approach. All samples possessed the same zinc blende structure. Surfactant cetyltrimethyl ammonium bromide (CTAB) exerts a major influence in directing the formation of these microstructures. By adding the CTAB into the reaction mixture, the cubes of the ZnS:Mn microstructures gradually dissolved to form larger microspheres. These microspheres are composed of an extensive growth of nanoparticles, which can be connected to each other. By increasing the concentrations of CTAB, these microspheres transformed into ZnS:Mn nanospheres. The photoluminescence emission showed a strong and broad peak centered at 594 nm for all samples due to the presence of 4T1 → 6A1 transition of the Mn2+ ion. A broad excitation peak centered at 263 and 327 nm is shown in all samples. Because the products show strong luminescent emissions and variety morphologies, they could be readily fabricated into devices for use in phosphor applications.

The photophysical properties of MSnO3 (M = Ca, Sr, and Ba) including optical absorption, photoluminescence, and energy band structure including band edge positions were investigated experimentally and theoretically in association with their photocatalytic properties. Photocatalytic reactions for H2 and O2 evolution in the case of sacrificial reagents were performed under ultraviolet (UV) light irradiation. The order of the activities of H2 evolution was CaSnO3 > SrSnO3 > BaSnO3, agreeing not only with that of the conduction-band edges (or band gaps) but also with that of the transferred excitation energy, while that of O2 evolution was CaSnO3 < SrSnO3 < BaSnO3, consistent with that of the angle of the Sn–O–Sn bonds as well as the delocalization of excited energy. When loaded with RuO2 cocatalyst, both CaSnO3 and SrSnO3 can efficiently split pure water into hydrogen and oxygen in a stoichiometric ratio under UV light irradiation. In addition, RuO2-loaded SrSnO3 showed higher water splitting activity than RuO2-loaded CaSnO3 did. This is attributed to the suitable conduction and valence band edges and to high mobility of the photogenerated charge carriers caused by the proper distortion of SnO6 connection in SrSnO3. The RuO2-loaded BaSnO3 photocatalyst cannot split pure water, which might be because of a high concentration of defect centers such as Sn2+ ions and the probability of radiative recombination in BaSnO3.

Compressive deformation was experimentally investigated for Ti41.5Cu42.5Zr2.5Hf5Ni7.5Si1 bulk metallic glass (BMG) fabricated at different cooling rates. It was found that the ductility of the BMG alloy increased with increasing of the cooling rate in solidification. The alloy with a monolithic amorphous structure exhibited a large ductility, up to 12%. The effect of cooling rate on the ductility of the BMG alloy is interpreted in terms of the variation in amorphous nature and free volume of the as-cast materials.

(100)-/(001)-oriented epitaxial Pb(Zr,Ti)O3(PZT) films with various Zr/(Zr + Ti) ratios and film thicknesses were grown on (100)cSrRuO3//(100)SrTiO3substrates at 600 °C by metalorganic chemical vapor deposition. Their crystal structure and microstructure consisting of particularly mixed phases with tetragonal and rhombohedral symmetries were investigated in detail. Films with the mixed phases with tetragonal and rhombohedral symmetries were ascertained at a Zr/(Zr + Ti) ratio of around 0.50 at a thickness of more than 200 nm from x-ray diffraction (XRD) analysis, while no mixed phase region was observed for 50 nm thick film. The relative volume fraction of the tetragonal cdomain decreased with increasing film thickness for 2-μm-thick films with mixed phases, while the tetragonal adomain and rhombohedral domain increased. These mixed phases were ascertained to have originated from the same cubic PZT grown above Curie temperature from results obtained by temperature-dependent high-resolution XRD reciprocal space mapping. The transmission electron microscopy images clearly revealed that the microstructure of the film gradually changed along the film thickness, despite the fact that the film was very uniform. Tetragonal phases were dominant in the bottom region (near the interface with the substrate) of the film, while rhombohedral phase was dominant in the upper region (near the surface), which was also ascertained by cross-sectional Raman analysis. In addition, the tetragonal a/cdomain was wider in the bottom region than that in the upper region of film with mixed phases. These data clearly demonstrate that both the crystal structure and microstructure changed along the film thickness.

Cs-type layered manganese oxide with a novel hexagonal-like morphology (Cs–BirMO) was prepared by a solid-state reaction procedure. The Cs+ extraction and alkali–metal ion insertion reactions were investigated by chemical analyses, x-ray analyses, scanning electron microscopy observation, Fourier transform-infrared spectroscopy, thermogravimetric differential thermal analyses, pH titration, and distribution coefficient (Kd) measurements. A considerable percentage (88%) of Cs+ ions in the interlayer sites were topotactically extracted by acid treatment, accompanied by a slight change of the lattice parameters. Alkali–metal ions could be inserted into the interlayer of the acid-treated sample (H–BirMO), mainly by an ion-exchange mechanism. The pH titration curve of the H–BirMO sample showed a simple monobasic acid toward Li+, Rb+, and Cs+ ions, and dibasic acid behavior toward Na+ and K+ ions. The order of the apparent capacity was K+ > Li+ ≈ Na+ ≈ Rb+ ≈ Cs+ at pH < 6. The Kd study showed the selectivity sequence of K+ > Rb+ > Na+ > Li+ for alkali–metal ions at the range of pH <5; H–BirMO sample showed markedly high selectivity for the adsorption of K+ ions. Preliminary investigations of the electrochemical properties of the Li+-inserted sample Li–BirMO(1M, 6d) showed that the obtained samples had a relatively high discharge capacity of 115 mAh g−1 and excellent layered stability.

Co-based brazing alloy CoFeNi(Si, B)CrTi was designed for SiC joining. The periodic banded reaction structure that existed at the interface between SiC and the traditional Ni-based or Co-based braze has been eliminated by the new brazing alloy. The maximum room-temperature four-point bend strength of 161 MPa was achieved for SiC/SiC joint under the optimum brazing condition of brazing filler thickness of 120 μm, brazing temperature of 1150 °C, and brazing time of 10 min. The corresponding reaction layer of the SiC/SiC joint is composed of multilayer silicides and TiC band, and many small TiC particles are scattered throughout the matrix of the central part of the joint. The joints thus exhibit stable high-temperature strength. It is believed that the formation of TiC in the joint contributes not only to the elimination of the periodic banded reaction structure, but also to the high joint strength and the high-temperature stability.

This work reports on a new morphology-inheriting methodology to MgO nanoplates. Precursor of Mg(OH)2 nanoplates was synthesized by a solvothermal method and showed a hexagonal shape. The morphological features of Mg(OH)2 nanoplates were retained to the resulting MgO nanoplates using a programmed heating process. MgO nanoplates showed highly hydroxylated surfaces. Upon excitation, the interactions between hydroxyl groups and surface O2−4c and O2−3c species gave rise to a dominant ultraviolet emission at 415 nm.

In a hydrophobic zeolite, the infiltration and defiltration of water can be controlled by adjusting external pressure, and therefore the system behaves as a “liquid spring.” Since the hysteresis of sorption isotherm is negligible and the working pressure is thermally controllable, volume memory devices can be developed based on this phenomenon. With the addition of sodium chloride, both infiltration and defiltration pressures increase, which should be attributed to the cation exchange. The temperature sensitivity of the system increases with the electrolyte concentration, beneficial to improving the output energy density.

High quality, uniform PbZrxTi1-xO3(PZT) films were prepared on the 4 inch wafers by chemical solution deposition (CSD) of 1,3-propanediol precursors. Film uniformity was studied as a function of deposition conditions including spinning rates and co-solvents. Measurements of the surface tension and composition evolution during evaporation and spinning stages showed that the surface tension increases significantly when the co-solvent is nearly completely evaporated. The evaporation of the propanol co-solvent and volatile by-products occurs within the first 5 s of spinning giving rise to defects, whereas octanol is slowly evaporated during 60 s producing uniform coatings. Other co-solvents such as hexanol and pentanol produced uniform films as well. Therefore stabilization of the surface tension in the initial spinning stage is a key to prevent the defect formation. These findings facilitate the deposition of uniform PZT films over large substrates by a simple, scalable, and cost-effective process.

A fluorescence switch by the photoisomerization of a photochromic compound in CH3CN and in a polymer film using a bistable photochromic (1,2-bis(2-methylbenzo[b]thiophen-3-yl) hexafluorocyclopentene) (BTF6) and a fluorescent 3-(2-benzothiazolyl)-7-(diethylamino) coumarin (coumarin6) was demonstrated. Because only the closed form of BTF6 serves as a fluorescence quencher of coumarin6, and the read (406 nm), write (254 nm), and erase (>500 nm) wavelengths are well-separated, a reversible modulation of the fluorescence of coumarin6 with high contrast and high sensitivity is expected to be realized. This system may represent an alternative to the fluorescence switches that are based on covalent systems in the potentially long-term optical data or image storage schemes utilizing luminescence intensity readout.

We report measurements of the elastic properties of Zr-based bulk metallic glasses, Zr52.5Cu17.9Ni14.6Al10Ti5, Zr50Cu30Ni10Al10, and Zr50Cu40Al10 between 5 K and 300 K. Both the shear and longitudinal modulus have been measured as a function of temperature, allowing accurate determination of the Poisson’s ratio and the related ratio of bulk modulus to shear modulus, K/G. These data make it possible to assess the influence of the alloy’s composition on the mechanical properties and enable an evaluation of the correlation between the elastic moduli and the ductility of the alloys.

Single crystals of the multiferroic (1 − x)BiFeO3–xPbTiO3 (BF–PT) solid solution with a nominal morphotropic phase boundary (MPB) composition were grown from flux. Structural characterization by x-ray diffraction shows the simultaneous existence of a tetragonal, an orthorhombic, and a rhombohedral perovskite phase in the crystals. A high ferroelectric Curie point of 660 °C was found in the BF–PT crystals by dielectric measurements. The variation of the magnetic moment as a function of temperature of the BF–PT crystals measured under zero field cooling mode reveals three anomalies with the highest one around 440 K, corresponding to the antiferromagnetic ordering temperatures of the rhombohedral, orthorhombic, and tetragonal phases, respectively. These results demonstrate the intrinsic relations between the MPB phase components and the macroscopic ferroic properties.

An analysis of size effects and doping on the strength of ultrananocrystalline diamond (UNCD) thin films is presented. The doping was achieved by the addition of nitrogen gas to the Ar/CH4 microwave plasma. The strength data, obtained by means of the membrane deflection experiment (MDE) were interpreted using Weibull statistics. The validity and predictive capability of the theory were examined in conjunction with detailed fractographic and transmission electron microscopy microstructural analysis. The Weibull parameters were estimated nonlinear regression based on 480 tests when the specimen volume varied from 500 to 16,000 μm3. Both undoped and doped UNCD films exhibited a decrease in strength with an increase in specimen size. A significant drop in strength was measured when the films were doped with nitrogen. Such a drop was almost independent of the percentage of doping. The results also showed that one can predict the fracture strength of a component possessing any arbitrary volume to within ±3%. Moreover, the failure mode of UNCD was found to be volume controlled. We also report changes in Young’s modulus as a function of doping for n-doped UNCD thin films.