The exothermic process that occurs around 700 K during calcination of ZrO2−x(OH)2x, associated with the crystallization of the low-temperature tetragonal metastable phase of ZrO2, was analyzed using x-ray diffraction, high-resolution thermogravimetric analysis (TGA), nitrogen adsorption, and modulated differential scanning calorimetry (MDSC). High-resolution TGA allowed us to determine the water loss, resulting from condensation of OH− groups. The amount was 0.137 wt% in our case, equivalent to 1.7 × 10−2 mol of H2O/mol of ZrO2. That corresponds to about one −OH group per nm2 being lost in that process. By using MDSC we determined that the change in enthalpy (∆Hglobal = −15.49 kJ/mol of ZrO2) was the result of two parallel contributions. One of them was reversible and endothermic (∆Hrev = 0.11 kJ/mol of ZrO2), whereas the other was irreversible and exothermic (∆Hirrev = −15.60 kJ/mol of ZrO2). The variability and magnitude of the exotherm, as well as the fact that the accompanying weight loss is so small, are consistent with a mechanism involving the formation of tetragonal nuclei, rather than global crystallization, and hence depend on the number of nuclei so formed.

Quantum atomistic simulations of crystalline silicon and germanium have been carried out by the path-integral Monte Carlo method. The interatomic interactions were modeled by Stillinger–Weber-type potentials, with parameters adequate to quantum simulations. Quantum zero-point motion together with anharmonicity of the interatomic potential led to a lattice expansion of 7 × 10−3 Å for both Si and Ge. Results for the equation-of-state (volume versus pressure) and for the thermal expansion coefficient agreed well with experimental results for both materials at T > 100 K and for hydrostatic pressures up to 100 kbar.

An infiltration and growth process has been developed to produce single-domain Yba2Cu3Oy(123) as thick films on various substrates or as self-supporting fabrics. Commercially available Y2O3 cloths of square woven or satin woven structure were infiltrated with liquid phases from a suitable source containing barium cuprates and copper oxides and subsequently converted into Y2BaCuO5(211) and −123 phases by a series of distinct peritectic reactions. Depending on the final form of 123, the Y2O3 cloth was either clamped firmly at corners to produce a self-supporting 123 fabric or placed on a suitable substrate to result in a thick film coating of 123. The source material for the liquid phase being in the form of solid blocks was placed at corners of the cloth in the case of free-standing 123 fabrics. In case of the thick film configuration the liquid phase powder was spread on the surface of the Y2O3 cloth. A small c-axis-oriented MgO or Nd(123) seed was used to generate an oriented 123 domain in the infiltrated fabric. The solidification process was optimized to transform the entire Y2O3 fabric into a single-domain 123. The microstructure of the single domain was optimized in terms of 211 size and content for high Jc. A detailed description of the process, the growth mechanism, the resulting microstructures was given, and basic superconducting properties of the new form of 123 are briefly discussed.

Changes in mass density of amorphous Pd80Si20 were monitored in situ during irradiation with He2+ and H+ ions at temperatures below 100 K and during subsequent thermal treatment. The mass density decreased with increasing ion fluence and exponentially approached a saturation value of −1.2%, corresponding to a recombination volume of 190 atomic volumes. The initial swelling rate was 2.3 atomic volumes/displaced atom. The mass density of the irradiated material increased during subsequent thermal treatment, and the irradiation-induced decrease of the mass density recovered completely at room temperature.

Single crystals of 67Pb(Mg1/3Nb2/3)O3–33PbTiO3 (PMN-PT, PMNT) relaxor-based complex perovskite solid solution grown by Bridgman method have pseudo-cubic symmetry under ambient conditions. Examination by means of polarized light microscopy showed that the microstructure of the crystals was dominated by a large number of coarse twin domains. It was confirmed that the most common composition planes were {110} in addition, {112} planes were also observed. These twins may be associated with the transformation of PMNT complex perovskite from the cubic to tetragonal upon a decrease in temperatures. The morphology of the domain structure may be explained from the theory of martensitic transformation.

A series of carbon coatings was deposited on a 1040 SiC monofilament using chemical vapor deposition, and failure of the fiber-matrix interfacial region under transverse tension was studied. Deposition substrate temperatures were approximately 920, 1000, and 1080 °C, and all other deposition parameters were held constant. The microstructures of these carbon-coated fibers were examined using optical microscopy, scanning electron microscopy, and transmission electron microscopy (TEM). TEM observations were made using bright-field imaging, dark-field imaging, selected-area diffraction, and high-resolution lattice imaging. Tensile testing of single-fiber composite samples was performed transverse to the fiber axis to determine the stress required to cause debonding of the fiber from the titanium alloy matrix. Adhesion experiments were used to examine differences in bond strength of the SiC–C interfaces of the three coatings. A systematic increase in the grain size of the SiC substrate fiber within 3 μm of the SiC–C interface with increasing deposition temperature was observed. The crystallographic texturing of the basic structural units of carbon within the coatings was also found to increase with increasing deposition temperature. The SiC–C interface strength increased with increasing deposition temperature and correlates with the microstructural changes in both the SiC and carbon at the interface. The overall composite transverse strength was not affected by the change in deposition temperature, although the fracture location was affected. The carbon coating with the lowest SiC–C interface strength failed at this interface, and the coatings with more highly textured carbon failed within the coating, where the proportion of weak van der Waals bonds parallel to the tensile direction was correspondingly higher.

A study was made of the effects of whisker content and dimensions on the R-curve behavior of an alumina matrix composite reinforced with silicon carbide whiskers. Experiments showed that the rising R-curve behavior is strongly enhanced by the increase in the volume fraction and the size of whiskers. Simulation based on a model of crack face whisker bridgings was made to elucidate the effects on the R-curve of the composite. The validity of the simulation was confirmed by good agreement between the experimental and the calculated R-curves. In addition to the R-curve, the distribution of crack closure stresses as well as crack tip opening displacements was also calculated, which directly reflects crack face whisker bridging processes in the composite. Then the dependence of whisker content and dimensions on the R-curve was analytically discussed taking the bridging processes into account.

Microscopic effects of self-radiation damage in 244Cm-doped LuPO4 crystals were examined with transmission electron microscopy. These LuPO4 crystals had been doped with 1 wt% 244Cm and exposed to a radiation dose as high as 5 × 1016 α-decay events/mg over 18 years. The microscopic analysis revealed dense arrays of individual defect clusters and numerous bubbles. Whereas, the defect clusters may be interpreted as residuals of alpha-recoil tracks, the bubbles likely resulted from the α-particles generated during the decay events. The bubbles were found to coalesce under electron beam irradiation. Despite the high accumulated dose over the 18 years, the samples exhibited sharp diffraction patterns and periodic lattice spacings. This finding indicated that the samples remained largely crystalline and that the radiation-induced lattice damage was recovered at a rate comparable to that of damage production. This high recoverability is discussed with respect of various annealing processes that may have occurred in the samples.

In situ straining transmission electron microscopy (TEM) experiments were performed to study the propagation of the shear bands in the Zr56.3Ti13.8Cu6.9Ni5.6Nb5.0Be12.5 bulk metallic glass based composite. Contrast in TEM images produced by shear bands in metallic glass and quantitative parameters of the shear bands were analyzed. It was determined that, at a large amount of shear in the glass, the localization of deformation occurs in the crystalline phase, where formation of dislocations within the narrow bands are observed.

A solid polythiophene pellet was ablated by a KrF excimer laser beam to deposit thin films on silicon substrates. The laser-ablated plasma was studied by optical emission spectroscopy to identify the photon-breaking of C–S bonds in the ablated heterocycles. Raman and x-ray photoelectron spectroscopy measurements of the deposited thin films also supported the selective photon-induced bond breaking. After eliminating sulfur in the molecular structures, the thin films appeared to be composed of cubic nanocrystals with a uniform size of 240 nm. X-ray diffraction measurement determined the cubic crystal structures with a lattice constant of α =3.38 Å and suggested a quasi-onedimensional carbon chain structure along the body diagonal of the cube.

The fabrication of rodlike Ca α-sialon crystals through a combustion synthesis process is reported in this paper. The main morphological features in the product included rodlike crystals, two dimensional elongated platelets, and equiaxed particles. By proper adjustment of the combustion parameters, a high productivity of rodlike Ca α-sialon crystals in the final product could be achieved. The combustion reaction mechanism and the relationship between the combustion parameters and the particle morphology were investigated.

Combinatorial libraries of the mixed oxide system Cu1−xCexO3 (0 ≤ x ≤ 1) have been generated using a modified Pechini powder synthesis process in conjunction with inkjet deposition. Mixed oxide crystalline powders were formed at temperatures below 500 °C. These powders have particle sizes in the range of 20.0 to 85.5 nm, and the powder surface area increases with cerium content. In addition, each of the mixed oxides (0 < x < 1) displayed catalytic activity in the CO oxidation reaction at temperatures between 150 and 350 °C. This novel protocol has also been used to generate a library of oxide powders of the perovskite-like La1−xSrxCoO3?δ system. The La–Sr–Co–O system from this protocol exhibits lower average surface areas than the Cu–Ce–O system (approximately 11.2 m2/g) due to higher decomposition temperatures but still acts as an active catalyst for the CO oxidation reaction.

Multilayers of tungsten carbide/carbon (WC/C) deposited by physical vapor deposition onto steel substrates were subjected to depth-sensing indentation testing. The investigation aimed at probing the influence of dissimilarities between the microstructure of the multilayers and substrate on the system mechanical properties. The resultant load-displacement data were analyzed both by conventional load-displacement (P-δ) and load-displacement squared (P-δ2) plots. Furthermore, it was demonstrated that the occurrence of annular through-thickness cracks around the indentation sites can be identified from the load-displacement curve. Also, analysis of the lower part of the unloading curve permitted us to identify whether the coating had popped up by localized fracture. The cracking mechanism was characterized using a new technique for cross-sectional electron microscopy of the nanoindentations. The information retrieved with this technique eliminates the problems, inherent in assessing at this small contact scales, whether the fracture is by coating decohesion or by interfacial failure. In our case, it was demonstrated that the failure mechanism was decohesion of the carbon lamellae within the multilayers. The mechanical properties (hardness and effective Young's modulus) were also assessed by nanoindentation. The hysteresis loops were analyzed and discussed in terms of the method developed by Oliver and Pharr [J. Mater. Res. 7, 1564 (1992)].

A ceramic ink was prepared, characterised, and subjected to continuous ink-jet printing. The optimum modulation frequency for printing was estimated. The surface free energies of several substrates were determined and different patterns of the ink droplets were printed on these. Phenomena occurring during the process were investigated. The drop-by-drop resolution and ink spreading were found to be dependent on the dispersive/total surface free energy ratio of the substrates. Ink drying was accompanied by powder migration in the droplets deposited on substrates with a surface free energy lower than the surface tension of the ink. Printing of multiple layers was accompanied by the appearance of ridges, splattering, and non-vertical walls. The causes of these phenomena are discussed in this paper.

A low-power, atmospheric pressure, microwave plasma torch was used to make spherical alumina particles of controlled size from irregularly shaped precursor powders. Detailed studies of the impact of operating parameters, particularly gas identity (argon or air), gas flow rates, and applied power, showed that particle size changed in a predictable fashion. The most important factor in controlling particle size appears to be precursor particle density in the aerosol stream that enters the plasma hot zone. This and other facts suggest that particle collision rate is primarily responsible for determining ultimate particle size, although atomic addition also plays a role. Reproducible volume average particle sizes ranging from 97 to 1150 μm3 were formed from precursor particles of order 14 μm3. Moreover, for the first time we report the creation of an atmospheric pressure low-power air plasma (<1 kW).

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.

Polycrystalline sample of Bi2FeNbO7 was synthesized by the solid-state reaction and characterized by powder x-ray diffraction and Rietveld structure refinement. The optical absorption and structural properties of Bi2FeNbO7 were investigated. It was found that the Bi2FeNbO7 compound has the pyrochlore crystal structure, cubic system with space group Fd3m, and the lattice parameter is a = 10.5233(2) Å. Ultraviolet-visible diffuse reflectance spectroscopy measurement revealed that the band gap of Bi2FeNbO7 is about 2.1(6) eV.

Electron backscatter diffraction (EBSD) has been applied to characterize Pb(Mg1/3Nb2/3)O3–35 mol%PbTiO3 single crystals grown by the seeded polycrystal conversion method. Macroscopically triangular crystal growth fronts were shown to each be associated with discrete crystals that originated from slightly misoriented segments of an initially cracked single-crystal seed plate. Various types of crystal imperfections, including voids, second-phase regions, and polycrystalline matrix grains trapped within the grown region, were readily identified and distinguished from one another using EBSD. Further, it was shown that trapped matrix grains in the grown region had consistently small misorientations with respect to the grown single crystal and this may be qualitatively explained by a simple boundary energetics argument. The significance of the trapped grains is discussed.

Formation of ordered structure in flux-grown Ba(Mg1/3Ta2/3)O3(BMT) single crystals was studied using x-ray diffraction, electron diffraction, and high-resolution electron microscopy. The low-temperature-grown crystals exhibited no sign of B-site ordering. Annealing at 1500 °C induced the 1:2 ordered phase, and its content increased with the annealing time. The superlattice diffraction peaks were broad initially; they sharpened rapidly with the annealing time. Diffuse superlattice reflections were found in electron diffraction patterns of 1500 °C annealed BMT; they turned into sharp reflections under long annealing time or higher temperature, 1600 °C. The intensity of diffuse reflections was sparsely distributed, but the maximum intensity location was determined in the digitized recording of image plate. The maximum intensity sites of two diffuse reflections in the 〈111〉 direction deviated from the presumed 1/3 and 2/3 positions and shifted towards the center. The diffuse reflection and the deviation from regular positions were interpreted as the composition modulation during B-site cation diffusion.

Nanoindentation combined with atomic force microscopy was applied to measure the fracture toughness of polystyrene/glass interfaces. Film delamination occurs when the inelastic penetration depth approximately equals or exceeds the film thickness. The delamination size was accurately measured using atomic force microscopy. Using multilayer indentation and annular-plate analyses, the interfacial fracture toughness was then assessed. The values obtained from the two analyses are in good agreement with the fracture toughness of the interface being approximately 350 mJ/m2. By appropriate fracture surface characterization, it was shown that fracture occurs along the polystyrene/glass interface. Crack arrest marks were observed, and their possible cause discussed. On the basis of the morphology of the fracture surface, the fracture toughness was also evaluated using a process zone analysis. The result agrees well with those obtained from the other two analyses.