An extended microbridge test (eMBT) was proposed to assess the adhesion of metallic coatings on metallic substrates. Through loading on the backside of narrow striped freestanding coatings, a two-dimensional stable interfacial delamination was introduced. A cross-sectional scanning electron microscope (SEM) was used to examine the interfacial fracture process. A large deflection solution for elastic deformation of the coating was derived, and an approximate model was established for the estimate of interfacial crack extension force G. The eMBT samples of electroplated Ni coatings on C45 carbon steel substrate were tested, and the measured interfacial fracture toughness was about 5.28 J/m2. Cross-sectional SEM examination showed that the interface crack extended along the interface plane, and therefore the interfacial fracture proceeded by the debonding of Ni/steel interface.

The reaction mechanisms and related microstructures in the Cu/Si, Ru/Si, and Cu/Ru/Si metallization system were studied experimentally. With the help of sheet resistance measurements, x-ray diffraction, field-emission scanning electron microscopy, secondary ion mass spectroscopy, and transmission electron microscopy, the metallization structure with Ru barrier layer was observed to fail completely at temperatures around 700 °C, regardless of the Ru thickness because of the formation of polycrystalline Ru2Si3 followed by Cu3Si protrusions.

The enthalpies of the monoclinic to orthorhombic transition for a series of A2M3O12 (A = Al, Cr, Fe, In, and Sc; M = Mo or W) compounds were measured by differential scanning calorimetry, and entropies of transition were estimated. The enthalpies of formation from the binary oxides at 25 °C for several A2M3O12 samples were obtained from drop solution calorimetry in molten 3Na2O·4MoO3 at 702 °C. The monoclinic and orthorhombic phases of Sc2Mo3O12 and Sc2W3O12 are the only phases that are enthalpically stable under ambient conditions. The enthalpies of formation from the oxides (ΔHf,ox) for orthorhombic Sc2Mo3O12 and Sc2W3O12 are −47.2 ± 2.1 kJ/mol and −8.5 ± 2.7 kJ/mol, respectively. For Fe2Mo3O12, In2Mo3O12, and In2W3O12, ΔHf,ox values are 51.5 ± 4.5, 7.4 ± 2.9, and 44.5 ± 2.3 kJ/mol, respectively. These phases are entropically stabilized and/or metastable. Enthalpies of formation for phases that could not be measured by calorimetry have been estimated from the enthalpies of transition or trends in the enthalpies of formation. In general, the monoclinic phase is slightly enthalpically stabilized over the orthorhombic phase, while transition to the orthorhombic phase is entropically favored. This confirms that the orthorhombic phase is stable at high temperatures, the monoclinic is stable at low temperatures, and the monoclinic to orthorhombic transition is reversible.

The effect of the substrate surface, structure, and chemistry on the interfacial interaction in Ni(thin film)/SiC was examined, with a focus on the recently discovered formation of a nickel intercalated graphite phase. Very thin Ni films (∼7 nm) were deposited onto heated 6H–SiC(0001) substrates prepared with: (i) an oxide layer, (ii) a surface reconstruction, and (iii) a pristine surface (no oxide and no reconstruction), followed by further annealing. Characterization using x-ray diffraction and atomic force microscopy revealed remarkable differences between the samples in terms of both surface morphology and crystallography. Nickel silicides were present in all samples; however, the phase composition differed depending on sample preparation. Furthermore, the pristine surface was the only one that clearly promoted the growth of the nickel graphite intercalation compound (Ni-GIC).

Near infrared (NIR) absorbing nanoparticles synthesized by the reduction of HAuCl4 with Na2S exhibited absorption bands at ∼530 nm, and in the NIR region of 650–1100 nm. The NIR optical properties were not found to be related to the earlier proposed Au2S–Au core-shell microstructure in previous studies. From a detailed study of the structure and microstructure of as-synthesized particles in this work, S-containing, Au-rich, multiply-twinned nanoparticles were found to exhibit NIR absorption. They consisted of amorphous AuxS (where x = 2), mostly well mixed within crystalline Au, with a small degree of surface segregation of S. Therefore, NIR absorption was likely due to interfacial effects on particle polarization from the introduction of AuxS into Au particles, and not the dielectric confinement of plasmons associated with a core-shell microstructure.

Degradation of insulation resistance due to the formation of the Y2Ti2O7 (pyrochlore) phases in yttrium(Y)-doped BaTiO3 ceramics was investigated. The addition of Y2O3 and sintering aid SiO2 to the BaTiO3 ceramics caused the formation of barium-related BaSiO3 and titanium-related Y2Ti2O7 second phases. The appearance of the abnormally grown large pyrochlore grains with the increase of sintering temperature critically degraded insulation resistance at high temperatures. When the volume fraction of the pyrochlore phase increased, the resistance degradation was also observed although the grain size of the pyrochlore phase became smaller. The highly oxygen ionic conductive nature of the Y2Ti2O7 pyrochlore phase is supposed to accelerate electromigration of oxygen vacancies resulting in the resistance degradation. The formation of pyrochlore phase should be prevented to guarantee the high-temperature reliability of BaTiO3 bases ceramic capacitors.

Magnesium hydroxide nanoneedles and nanorods were synthesized by reverse precipitation in the presence of polyethylene glycol (MW 1000) at ambient temperature. The obtained magnesium hydroxide crystals were characterized in terms of morphology, particle size, crystal structure, and thermal stability by high-resolution transmission electron microscopy, x-ray diffraction, infrared spectroscopy, and thermogravimetric and differential thermal analysis. The experimental results show that the growth of magnesium hydroxide crystals and the dispersivity of the nanostructures were greatly influenced by polymer dispersant. The mechanism of the formation of magnesium hydroxide nanorods and nanoneedles was also proposed.

The goal of this work was to improve the strength of sintered zirconia (3 mol% yttria stabilized) by surface treatment, using a low expansion glass (Mg3Al2Si6O18) at high temperature. The room-temperature strength was increased by about 42% when the glass was penetrated for 30 min. There was a drastic increase in the Weibull modulus. However, the longer holding time led to grain coarsening and the excess glass deteriorated the strength. The magnitude of the strength increment was on the order of surface stress measured experimentally and thermo-elastic stress predicted theoretically. A significant contribution of phase transformation of zirconia from tetragonal to monoclinic phase on the residual stress was also found. Furthermore, compared to the as-sintered zirconia, the glass-treated sample (penetrated for 30 min) exhibited relatively higher strength at elevated temperature (750 °C) and also showed a significant improvement in the thermal shock resistance behavior.

In this study, we investigated the role of a minor alloying element in improving the plasticity of amorphous alloys. The plasticity of the amorphous alloys, Cu60−xZr30Ti10Bex, was drastically improved with increasing amount of Be and reached a maximum of 23% at Cu53Zr30Ti10Be7. It was observed that an atomistic-scale phase separation existed within the alloy, which resulted from the large difference in mixing enthalpy between the binary pairs (Be–Cu, Be–Zr). This atomistic-scale phase separation resulted in an open structure in which atomic rearrangements in the form of the creation of free volume and crystallization were facilitated during deformation. Here we discuss the origin of the enhanced plasticity by clarifying the effect of an additional element, whose mixing enthalpies with the major elements are significantly different, on the structural change of the amorphous alloy.

P-doped titanium dioxide (TiO2) nanoparticles were synthesized using a sol-gel method. The ethanol solution of Ti(OC2H5)4 was mixed with an aqueous solution of H3PO4 to undergo hydrolysis and polycondensation at 90 °C for 4 h. The resultant solids were centrifugally filtered, dried, and then calcined at different temperatures, followed by chemical and physical characterization. At an atomic ratio of P/Ti = 0.03, the formed P-doped TiO2 can preserve its anatase structure at 900 °C for 3 h, with no formation of other phases. Further increasing the P/Ti atomic ratio in the P-doped TiO2 may stabilize the anatase–TiO2 at even higher temperatures but may lead to the formation of TiP2O7 or (TiO)2P2O7. A test of photocatalysis showed that the P-doped TiO2 nanoparticles, with a P/Ti ratio = 0.03 and after being calcined at temperatures between 400 and 800 °C, can decompose ⩾98 mol.% of the methylene blue (MB) after 30 min of irradiation by 365-nm ultraviolet light, while P25 particles can only decompose 71 mol% of the MB.

The electrochemical corrosion behavior of Sn–XAg–0.5Cu alloys in 3.5% NaCl solution was examined using potentiodynamic polarization techniques. The Ag content in the alloy was varied from 1 to 4 wt%. The polarization curves obtained for the alloys show an active–passive transition followed by a transpassive region. Sn–XAg–0.5Cu alloys with higher Ag content (>2 wt%) show a strong tendency toward passivation. The passivation behavior has been ascribed to the presence of both SnO and SnO2 on the anode surface. Increase in Ag content from 1 to 4 wt% results in a decrease in the corrosion-current density (Icorr) and linear polarization resistance (LPR) of the alloy. Nevertheless, the corrosion potential (Ecorr) shifts toward negative values, and a decrease in corrosion rate is observed. The presence of Cl− ion initiates pitting and is responsible for the rupture of the passive layer at a certain breakdown potential. The breakdown potential (EBR) decreases and shifts toward more noble values with increase in Ag content in the alloy. Surface analyses by x-ray photoelectron spectroscopy (XPS) and Auger depth profile studies confirmed the formation of both Sn(II) and Sn(IV) oxides in the passive layer.

The evolution of the kinetic energy distribution of photoelectrons from a cube-oriented aluminum sample during tensile deformation was probed with a retarding field energy analyzer. Because of the anisotropy of the aluminum work function, the electron-energy distribution is altered as the area fractions of the major surface planes change during deformation. In cube-textured aluminum, deformation reduces the {100} area fraction and the relatively low energy electrons from these surfaces. Conversely, the {110} and {111} area fractions and the relatively high energy electrons from these surfaces both increase. These changes are quantitatively consistent with texture analysis by electron backscattered diffraction (EBSD). They reflect deformation-induced production of {111} surfaces by slip and the exposure of {110} surfaces by grain rotation. Photoelectron kinetic energy measurements supplement EBSD measurements and are readily acquired in real-time.

Two new oxide photocatalysts in the Pb–Mg–Nb ternary system, Pb3MgNb2O9 (PMN) and Pb1.83Mg0.29Nb1.71O6.39, have been synthesized, and their photophysical and photocatalytic properties were investigated for the first time. The band gaps of PMN and Pb1.83Mg0.29Nb1.71O6.39 were estimated to be 3.2 and 2.8 eV, respectively, from their absorption spectra. The photocatalytic activity evaluated from the decomposition of 2-propanol into acetone under visible-light irradiation indicated that Pb1.83Mg0.29Nb1.71O6.39 exhibited at least 20 times higher activity than PMN and has a strong oxidizing potential to mineralize organic compounds.

Fracture toughness and its deformed structures were investigated on a Mg–3Al–1Zn (AZ31) alloy processed by direct extrusion. The average grain sizes of the alloy after extrusion at temperatures of 473 and 573 K were 4.0 and 14.5 μm, respectively (i.e., fine-grained and coarse-grained alloys). The plane-strain fracture toughness, KIC, as determined by stretched zone analysis in fine-grained and coarse-grained alloys was estimated to be 24.9 and 22.7 MPam1/2, respectively. Microstructural observations of the fine-grained alloy after fracture toughness testing showed that non-basal slip and grain-boundary sliding was activated even at room temperature. In addition, the {10-12} deformation twins were observed despite the fine-grained structures. However, the fraction of deformation twins was reduced with grain refinement, which related to the enhancement of fracture toughness with grain refinement.

A highly crystallized and smooth-surfaced zirconia (ZrO2) thin film was prepared using a precursor solution with 2,4-pentanedione addition (molar ratio of 1:1 for zirconium alkoxide); the film was irradiated with ultraviolet (UV) light using an ultrahigh-pressure mercury lamp. This thin film was compared with another thin film, which prepared using a precursor solution without additives and UV irradiation. The crystallinity of ZrO2 thin films improved with increasing 2,4-pentanedione addition and UV irradiation time and changed according to the type of organic additives. These results occurred presumably because the orientation of polymerization in zirconium alkoxide units and stability of chelate compounds for UV irradiation were controlled under these conditions. In addition, the method was effective for lower-temperature crystallization of highly crystallized, smooth-surfaced thin films.

Recently published results for a rigid spherical indenter contacting a thin, linear elastic coating on a rigid planar substrate have been extended to include the case of two contacting spheres, where each sphere is rigid and coated with a thin, linear elastic material. This is done by using an appropriately chosen effective radius and coating modulus. The earlier work has also been extended to provide analytical results that span the transition between the previously derived Derjaguin–Müller–Toporov (DMT)-like (work of adhesion/coating-modulus ratio is small) and Johnson–Kendall–Roberts (JKR)-like (work of adhesion/coating-modulus ratio is large) limits.

High-quality doped GaN layers were grown on silicon substrates by radio frequency nitrogen plasma-assisted molecular-beam epitaxy. High-temperature-grown AlN (about 200 nm) was used as a buffer layer. In-growth doping was done using high-purity Si and Mg as n- and p-type dopants, respectively. X-ray diffraction revealed that monocrystalline GaN was obtained. This is in good agreement with the results of morphological study by atomic force microscopy. Micro-photoluminescence (PL) and micro-Raman spectroscopy were used to study the room-temperature optical properties of the doping films. No yellow-band emission was observed in the PL spectroscopy. From the Hall measurements, the resulting n-type doping concentration was measured to be (1–2) × 1019 cm−3. Fairly uniform hole concentration as high as (4–5) × 1020 cm−3 throughout the GaN crystal was achieved. In terms of the carrier concentration, it was found that the results determined from the Fourier transform infrared analysis are in good agreement with the results determined from the Hall measurements.

BaTiO3 particles were prepared by heating a suspension of titania derived from the hydrolysis of titanium isopropoxide in a barium hydroxide [Ba(OH)2] aqueous solution. Well-crystallized cubic phase BaTiO3 fine particles were obtained by heating at a temperature >328 K for 24 h. The morphology and size of the obtained particles were affected by the reaction temperature and the Ba(OH)2/titanium alkoxide molar ratio. The secondary particles with a larger size were obtained at a lower reaction temperature. The nucleation process of BaTiO3 depended on the reaction temperature. The formation mechanism of BaTiO3 and the formation kinetics were investigated by measuring the concentrations of Ba2+ ions in the solution during the heating process. The BaTiO3 particle formation occurred on the surface of the titania particles after strong adsorption of the Ba2+ ions from the solution. The experimental results showed that the heterogeneous nucleation of BaTiO3 occurred on the titania surface.