Electron microscopy was used to investigate microstructures of diamond single crystals prepared at high temperature and high pressure (HPHT) from the Fe–Ni–C system. Analysis through selected-area electron diffraction pattern suggests that the crystal structure of the HPHT-grown diamond is cubic; polycrystalline diamonds are contained in the diamond. Etch pits on the (111) surface of the diamond by scanning electron microscopy revealed the dislocation motion under the action of applied stress. An array of parallel dislocation lines taken with reflection of [110] was observed directly by transmission electron microscopy (TEM). Fringe distortions and concentric dislocation loops were examined by rotation moiré images, which arose from two overlapping (111) close-packed planes rotated with respect to each other at a 5° angle. The parallel dislocation lines, distorted fringes, and concentric dislocation loops might have derived from the micro-inclusions. The parallel layers with growth cellular interface by TEM provided direct evidence that the diamond grew from solution of carbon in the molten catalyst at HPHT and the growth interface diamond was not stable.

The effects of gravity on crystallization of ZrF2–BaF2–LaF3–AlF3–NaF glasses have been studied by utilizing NASA's KC135 aircraft and a sounding rocket. Fibers were heated to the crystallization temperature in unit and reduced gravity. The fibers processed in unit gravity exhibited crystallization, while fibers processed in reduced gravity showed no signs of crystallization. An explanation based on shear thinning of liquids is presented to explain these results.

Medium-range order in ion-implanted amorphous silicon has been observed using fluctuation electron microscopy. In fluctuation electron microscopy, variance of dark-field image intensity contains the information of high-order atomic correlations, primarily in medium-range order length scale (1–3 nm). Thermal annealing greatly reduces the order and leaves a random network. It appears that the free energy change previously observed on relaxation may therefore be associated with randomization of the network. In this paper, we discuss the origin of the medium-range order during implantation, which can be interpreted as a paracrystalline state, that is, a disordered network enclosing compacts of highly topologically ordered grains on the length scale of 1–3 nm with significant strain fields.

Hydrogen-free diamondlike carbon films were prepared on Si(100) with electron cyclotron wave-resonance plasma, which serves to sputter the graphite target and to simultaneously bombard the growing surface. Direct penetration of postionized carbon atoms (up to 140 eV) in addition to the momentum transfer from Ar plasma facilities the formation of the Ta–C structure. Surface morphology, mechanical, and optical properties of the deposits were examined with respect to the ion energy. Atomic force microscope images revealed island morphology in deposits with a typical root-mean-square roughness of 20 nm. A maximum content of about 70% for the fourfold-bonded structure was estimated from the Raman profiles, giving rise to a micro hardness of 60 ± 5 GPa.

An Al–Cu–Fe partial phase diagram involving the icosahedral quasicrystal has been constructed along an Al62.5Cu37.5−xFex (x = 2.5 to 25 at.%) isopleth. The icosahedral quasicrystal forms at 850 °C via a peritectic reaction between a liquid and (Al,Cu) 13Fe4 phase and coexists with a liquid phase at temperature below the peritectic reaction. The icosahedral quasicrystal crystallizes as a primary phase in the temperature range of 760 to 850 °C from alloys surrounded by composition points of Al–Cu–Fe: 62.5–33–4.5, 62.5–34.5–3, 57.5–39.5–3 and 57.5–38.0–4.5 at.%. On the basis of the phase diagram, single grains of the Al–Cu–Fe icosahedral quasicrystal with a maximum size of 5 mm were successfully grown from Al–Cu–Fe melts.

This paper proposes an evaluation method for the surface fracture behavior of coated glass or ceramic plates subjected to an impact with a small particle. The increase of the maximum stress and absorbed fracture energy measured from the back surface indicated the extent of the surface fracture that occurred in the simple soda lime glass and composite-lamina attached glass plates tested in a range of particle velocities up to 119 m/s. Impact surface-fracture indices expressed in terms of the maximum stress and absorbed energy are suggested as an effective evaluation parameter.

The local atomic structures in glassy, supercooled liquid and quasicrystalline phases for a Zr70Pd30 binary alloy have been examined by the x-ray diffraction method. It was found that the local atomic structure in the glassy phase can be identified as the distorted icosahedral-like structure around Zr and remains almost unchanged by the phase transformation into the supercooled liquid. In the formation process of the icosahedral phase, approximately one Zr atom substitutes with one Pd atom in this local structure. This kind of atomic rearrangement may improve the perfectibility of the as-quenched icosahedral-like cluster, leading to the phase evolution of the icosahedral phase.

It is shown that the substitution of reduced modulus for specimen modulus in the analysis equations for nanoindentation test data is valid. The methods of analysis use the slope of the unloading force–depth response which is assumed to be elastic. Because of this utilization of the slope or unloading stiffness, it makes no difference whether or not the deflection of the indenter is accommodated explicitly or transferred to that occurring within the specimen by artificially reducing the specimen modulus from its true value to lower value, the reduced modulus.

Composite separation membranes of poly(dimethylsiloxane) (PDMS) containing well-dispersed silicalite particles of 50 nm were successfully prepared and applied to the preferential pervaporation of acetic acid over water. The nanocomposite membranes showed improvement on both separation factor and permeation flux for the pervaporation process, as compared to plain PDMS membranes and composite membranes containing silicalite particles of 5 μm. The improvement can be attributed to higher readily accessible specific surface area and higher sorption selectivity toward acetic acid of the nano-size silicalite particles. Improvement on membrane thermal stability was also acquired through incorporation of nano-size silicalite particles.

Characteristics of the combustion synthesis of MoSi2 using elemental Mo and Si powder mixtures prepared by mechanical alloying were investigated. The mechanical alloying resulted in powders of pseudolamellar structure and a partial conversion of the elemental powders to hexagonal MoSi2 phase. Combustion reaction of the mixture was ignited around 670 °C, which is much lower than that with the powder prepared by low-energy ball milling. A mathematical model was developed to demonstrate the possibility of the ignition of the combustion reaction of the lamellar structure via a solid-state diffusional process. On the basis of model, effects of mechanical alloying time on the ignition temperature and combustion temperature are discussed.

For a few years, we had been concentrating on development of completely closed diamond synthesizing system aimed for microgravity experiments. Recently we started the new method with a graphite heater as carbon source. With this method, a completely closed system is successfully performed. In situ gaseous species analysis with gas chromatography and the possible reaction model is discussed.

The microstructure of La1–xAx(A = Ca or Sr)MnO3–δ thin films grown by liquid-delivery metalorganic chemical vapor deposition on (001) MgO and (110)pseudo-cubic LaAlO3 were studied by transmission electron microscopy. The La1–xCaxMnO3–δ thin film on large lattice mismatched MgO exhibited very defective microstructures and consisted of two typical regions. The first region was close to the film–substrate interface and had an epitaxial relationship to the substrate with many differently oriented domains nucleated on the substrate surface. The second region consisted of columnar grains with some degree of texture. In contrast, the smaller lattice-mismatched La1–xSrxMnO3–δ/(110)pseudo-cubic LaAlO3 film had good crystalline quality with highly oriented columnar grains but exhibited complicated dislocation structures. Apart from the misfit dislocations formed at the film–substrate interface, two types of anomalous dislocations with limited contribution to relieving misfit stresses were also observed. One type of dislocation had extra planes in the film and some climbed into the substrate. These dislocations were considered to form from dislocation loops during nucleation of the film. The other type of dislocations had extra planes parallel to the film–substrate interface and glided into the substrate side resulting in a 2° tilt of the film with respect to the substrate. The complicated dislocation configurations present in the sample were related to the complex strain field in the film. The relative strains along the interface measured in the film were heterogeneous. The variations of the strains in the film were related to the local Curie temperature changes and second-order phase transitions of the film.

Nanoindentation is a simple and effective means for evaluating the mechanical properties of thin films. In such circumstances, nanoindentation testers have been developed and commercialized by some companies. In this study, we tested the standard four specimens using six different types of testers and established a method to evaluate the nanoindentation data. The method requires only two correction factors; one is the frame compliance, Cf, of the testers, and the other is the error of the detection of the original surface which includes both the truncation of the indenter apex and the damage of the surface caused by the preloading of the indenter. The latter correction is conducted by adding a correction length, ΔhC, to the measured penetration depth, h. It was found that the values ΔhC increase with decrease in the hardness of material and are very sensitive to the performance of the testers.

Surface modification of polyimides has been used to obtain better interaction with an inorganic material. Copper sulfide incorporation onto the surface of commercial Kapton® polyimide showed that treatment with base was necessary for adherence of the copper sulfide to the polymeric matrix. The optimized conditions for composite preparation, obtained by response surface methodology, was pH 1.4 at 80 °C for 3.67 h. Using these conditions, we obtained electrical resistance as low as 1.0 ohm for CuS\Kapton® composites. These optimized conditions were used to prepare other low-resistance polyimide composites. The resulting composites were analyzed by photoelectron spectroscopy. The presence of S(2p) and Cu(2p) peaks demonstrated the incorporation of copper sulfide onto the polyimide surface. Scanning electron microphotographs and the images from atomic force microscopy showed a homogeneous CuS distribution in all composites.

Carbon nanotubes (CNTs) are always produced under a reductive ambient with hydrogen present using the chemical vapor deposition method. Oxidative media, such as carbon dioxide and oxygen, could damage the tubular structures by opening the nanotube ends or etching the tube walls. Here we report the synthesis of aligned defective, but clean, CNTs in the presence of water vapor. The tube walls were found broken as well as the tube ends. CNTs with a large amount of exposed broken sites on their tube walls have potential applications in many areas such as energy storage.

We report on needlelike silicon nitride nanowires grown on silicon using ammonia microwave plasma heating. Scanning electron microscope reveals that the nanoneedles are either straight, slightly bent, or kinked with sharp tips. Transmission electron microscope shows that the sizes of the nanowire tips are less than 5 nm and the structures are well crystallized. X-ray diffraction on the surface of the as-deposited structures indicates that both α-silicon nitride and β-silicon nitride exist. Catalyst particle splitting and merging explain observed structure derivation and bending. A vapor–liquid–solid model is employed to explain nucleation and growth mechanism.

BaTiO3-coating films were prepared from a solution containing poly(vinylpyrrolidone) (PVP) of molar composition Ba(CH3COO)2:Ti(OC2H5)4:PVP:CH3COOH:H2O: C2H5OH = 1:1:0.5:27:4:5, via nonrepetitive, single-step dip-coating. The gel films were found to be converted into BaTiO3 films via evaporation of the solvent and CH3COOH below 210 °C, decomposition of PVP at 210–360 °C, decomposition of CH3COO− below 440 °C, and crystallization at 500–610 °C. The decomposition of PVP was accompanied by the progress of the condensation reaction, which resulted in significant reduction in film thickness. When the gel films were heated isothermally at 700 °C, crack-free BaTiO3 films as thick as 0.9 μm were obtained. When the gel films were heated isothermally at 360 °C and then at 700 °C, the film became denser. Higher dielectric constants around 290 were found for the film that underwent the isothermal heat treatment at 360 °C. A slower rate of PVP decomposition was thought to be the key for the film densification.

Highly c-axis-oriented Bi3.25La0.75Ti3O12 (BLT) films with a homogeneous in-plane orientation were successfully grown on SiO2/Si(100) and Pt/Ti/SiO2/Si(100) substrates by a sol-coating route. The substitution of lanthanum ions for bismuth ions in the layered perovskite suppressed the formation of pyrochlore phase and enhanced the c-axis-oriented growth. The c-axis-oriented BLT film fabricated on a Pt/Ti/SiO2/Si(100) substrate showed fatigue-free characteristics with a large remanent polarization of 26–28 μC/cm2 and the coercive field of 50–75 kV/cm. These features significantly enhance the potential value of the BLT film for the applications to high-density ferroelectric random-access memories devices. In addition, the c-axis-oriented BLT film, with a homogeneous in-plane orientation on an amorphous surface, can be used as a suitable template material for applications to various electro-magneto-optic devices.

A relatively low-cost, high-efficiency method is reported to synthesize AlN nanowires, using carbon nanotubes as templates. The AlN nanowires were fabricated at 1100 °C, for 60 min. The diameters of the product could be roughly controlled by the sizes of carbon nanotubes selected as starting materials. The AlN nanowires obtained were among the thinnest ever known. X-ray diffraction, selected-area diffraction, energy dispersive spectroscopy, and high-resolution transmission electron microscopy, etc. were employed to characterize the products, which were found to be single crystals with some defects. The axes of the nanowires are normal to {1010} crystal planes. A new synthesis mechanism is proposed.

The structures and microstructures of a range of Aurivillius phases were investigated by transmission electron microscopy. Systematic rows of superlattice reflections arising from tilting of octahedra around the c axis were identified, and their intensities at room temperature were shown to diminish as the tolerance factor (t) of the perovskite blocks increased. For compounds with t's approaching 1, no superlattice reflections were observed. the paraelectric-to-ferroelectric phase transition temperature (Tc) was monitored through permittivity measurements as a function of temperature, and Tc was also shown to decrease as t increased. Consequently, the onset of octahedral tilting and Tc appeared to be strongly related Aurivillius phases. Planar defects arising from the structural phase transitions and from stacking irregularities were also discussed.