Highly (111)-oriented and conformal iridium (Ir) films were deposited by a liquid source metalorganic-chemical-vapor-deposition process on various substrates. An oxygen-assisted pyrolysis of (methylcyclopentadienyl) (1,5-cyclooctadiene) Ir precursor at a wide range of substrate temperatures (Tsub) between 300 and 700 °C was used. At a low Tsub of 350 °C, the randomly oriented polycrystalline films exhibited an I111/I200 x-ray intensity ratio of 6. However, the films deposited at Tsub = 700 °C on native SiO2 and amorphous SiO2 surfaces were highly oriented with the I111/I200 ratios of 277 and 186, respectively. The transmission electron microscopy study revealed continuous, dense, and faceted microstructures of Ir films. Also, the step coverage of Ir on TiN (64%) was higher than that on amorphous SiO2 (50%) surfaces.

The microstructures and phase compositions of Cu–Ag–Ti active-metal brazing alloys have been studied by scanning electron microscopy and energy dispersive x-ray spectroscopy to evaluate alloy wetting on AlN and Cu brazing on AlN. Titanium is segregated from the original alloy, and a Ti-rich layer is formed between the brazing alloy and AlN substrate. The alloy components are able to penetrate into the grain boundary of AlN during wetting or brazing, and the interfacial reaction takes place along the grain and outer boundary of AlN. The bonding of brazing alloys to AlN substrate often induces cracks in the AlN side.

The 90° macrodomains in tetragonal Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMNT) crystals take the shape of coarse and straight strips under optical microscopes and scanning electron acoustic microscopes. However, 71° or 109° domains in rhombohedral PMNT crystals are relatively poor in contrast and become clearer, coarser and straighter as their composition becomes closer to morphotropic phase boundaries, showing an evolution series of micro-to-macro domain transformation. Moreover, domain configurations are also dependent on the nucleation and growth rate of domains, the crystal defects, and the cooling rate through Curie temperature. The appearance of macrodomains arises from the strengthening of depolarization field and the weakening of random field.

Nanocrystalline Ag–Fe–Ni powders were produced by a reduction of the aqueous metal ion solutions with sodium borohydride and then converted to fine-grained silver–Invar alloys that offer attractive thermal, electrical, and mechanical properties. The samples were characterized by x-ray diffraction, scanning electron microscopy, wavelength dispersive x-ray spectrometry, thermomechanical analysis, microhardness measurements, and electrical conductivity measurements; thermal conductivity was estimated using the Wiedemann–Franz law. Sintering of a specimen with a nominal composition of 60 wt% Ag–25.6 wt% Fe–14.4 wt.% Ni led to the formation of a two-phase silver–Invar alloy with a grain size of approximately 2 μm, a hardness of 133 HK200g, coefficient of thermal expansion of 12.44 × 10−6 / °C, and electrical conductivity of 2.13 × 105 (Ω cm) −1.

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.

Aging properties of porous GaAs were investigated nondestructively using variable angle of incidence infrared spectroscopic ellipsometry. In addition to the thickness and volume porosity, properties of the solid part of the porous material are investigated in terms of the long-wavelength dielectric function and chemical composition. The high sensitivity is employed to detect and identify infrared resonant absorptions related to different vibration modes of cubic and amorphous As2O3. Resonances centered at 333.3, 480, 785.8, 838, and 1045.5 cm−1 are from cubic As2O3, whereas resonances centered at 350, 490, and 808.5 cm−1 are from amorphous As2O3.

Silicon microwires have been synthesized by the Taylor microwire process. In this process, silicon is melted inside a glass tube by a local heating source and fine microwire is then drawn out by mechanical pulling. The silicon microwire is encapsulated in a silica glass coating. Flexible 10–25-μm diameter polycrystalline silicon microwires were synthesized by this method in continuous lengths up to 460 mm.

Nacre (mother-of-pearl) from mollusc shells is a biologically formed lamellar ceramic. The inelastic deformation of this material has been experimentally examined, with a focus on understanding the underlying mechanisms. Slip along the lamellae tablet interface has been ascertained by testing in compression with the boundaries oriented at 45° to the loading axis. The steady-state shear resistance τss has been determined and inelastic strain shown to be as high as 8%. The inelastic deformation was realized by massive interlamellae shearing. Testing in tension parallel to the tablets indicates inelastic strain of about 1%, occurring at a steady-state stress, σsss ≈ 110 MPa. The strain was associated with the formation of multiple dilatation bands at the intertablet boundaries accompanied by interlamellae sliding. Nano-asperities on the aragonite tablets and their interposing topology provide the resistance to interfacial sliding and establish the level of the stress needed to attain the inelastic strain. Detailed mechanisms and their significance for the design of robust ceramics are discussed.

We present a simple and reproducible method to obtain TiO2 and Fe2O3 mixed-oxide thin films by reactive radio-frequency sputtering. The influence of iron concentration on the structural properties of the layers has been studied. Structural characterization, carried out by electron microscopy analysis, allowed one to correlate the inhibition of the grain growth of titania to the presence of iron oxide and to its segregation at grain boundaries. This behavior should be ascribed to a superficial-tension phenomenon. As a possible application of these thin films, we have investigated the gas-sensing properties toward CO, with particular focus on the role of Fe. The layers were capable to sense CO down to the level requested for environmental monitoring.

Stoichiometric barium titanate (BaTiO3) was synthesized in aqueous solution with acetone and/or methanol as additives to control the crystallization process. Adjusted nano-sized particles and narrow particle size distributions were achieved at 60 °C with additive concentrations up to 243 ml/ l. The growth kinetics showed that the additives influence the nucleation of the BaTiO3 particles and tend to suppress Ostwald ripening.

Deposition of highly textured diamond films on Si(001) has been achieved by using positively bias-enhanced nucleation in microwave plasma chemical vapor deposition. During the biasing period, an additional glow discharge due to the dc plasma effect appeared between the electrode and the substrate. The discharge is necessary for enhanced nucleation of diamond. X-ray diffraction, scanning electron microscopy, and cross-sectional transmission electron microscopy (XTEM) were used to characterize the microstructure of the diamond films on Si. The results show the morphology of diamond grains in square shape with strong diamond (001) texture. XTEM reveals that an amorphous interlayer formed on the smooth Si surface before diamond nucleation.

An icosahedral phase was found to be formed as a primary precipitation phase in the crystallization process of binary Zr70Pd30, ternary Zr70Ni30−xPdx, and Zr70Cu30−xPdx (x = 10 and 20 at.%) and quaternary Zr70Ni10Cu10Pd10 amorphous alloys. The maximum volume fraction of the icosahedral phase was nearly 100% for the 20% Pd alloys and the grain size tended to decrease in the range from 40 to 70 nm with increasing Pd content. No icosahedral phase was formed in the Zr–Ni–Cu alloys without Pd, and hence, the addition of Pd was concluded to be essential for the formation of the icosahedral phase in the Zr-based amorphous alloys. It also was noticed that the icosahedral phase was formed even in the binary Zr70Pd30 amorphous alloy. The icosahedral phase was in a metastable state and changes to equilibrium crystalline phases by annealing in the higher temperature range. The finding of the formation of the icosahedral phase in the binary alloy system allowed us to predict the future appearance of a number of icosahedral base alloys in other alloy systems.

A close relationship between the photoluminescence emissions labeled Y and S, related to dislocations and extended structural defects, and the preparation of the surface state of ZnSe single crystals before PL (photoluminescence) measurements has been established. The samples were obtained by solid-phase recrystallization under different pressure conditions. An easy method for achieving good quality surfaces with a very significant reduction of such Y and S PL emissions is proposed.

Values for the thermal conductivity κ and the thermal diffusivity D of four oxide single crystals were obtained. Near room temperature, the values for κ (W cm−1 K−1) and D (cm2 s−1) are as follows: LaAlO3, κ = 0.115, D = 0.0446; NdGaO3, κ = 0.068, D = 0.0197 for one structural orientation, and κ = 0.059, D = 0.0195 for an orthogonal orientation; (LaAlO3)0.3–SrAl0.5Ta0.5O3, κ = 0.051, D = 0.0133; and, ScAlMgO4, κ = 0.062, D = 0.0229. The relative standard uncertainties in these values are ±10% (1 σ). These values allowed us to calculate the specific heat of the materials. The thermal conductivity was measured by a dc heated bar method, and the thermal diffusivity was measured by a modification of Ångström's method.

A simple method is presented for measuring the characteristic spacing between striation defects that sometimes develop when coatings are deposited by the spin-coating process. Striation defects, because of their substantial regularity of thickness variation, are able to diffract laser light. By measuring the diffraction angle, it is possible to determine a characteristic spacing that corresponds to the most dominant spatial frequency for the striation defects that have formed. This diffraction technique is compared with other methods for determining the average striation spacing. This noncontact characterization technique may also be applicable to other regularly or quasi-regularly spaced defect structures that appear in coatings or other materials. The limits and accuracy of this technique are discussed in detail.

Nano-sized barium titanate (BaTiO3) particles prepared by the sol-to-precipitate method in aqueous/organic medium served to obtain thin-layer ceramic films of the tetragonal electroactive phase. Poly(methacrylic acid) works efficiently to process the suspensions and to obtain green films. Sintering the green films under O2–Ar atmosphere gave thin-layered ceramics of a thickness of 0.5–1.0 mm with a dielectric constant of 3750 at 20 °C (1 kHz).

A nanostructured 5083 Al–Mg alloy powder was subjected to various thermal heat treatments in an attempt to understand the fundamental mechanisms of recovery, recrystallization and grain growth as they apply to nanostructured materials. A low-temperature stress relaxation process associated with reordering of the grain boundaries was found to occur at 158 °C. A bimodal restructuring of the grains occurred at 307 °C for the unconstrained grains and 381 °C for the constrained grains. An approximate activation energy of 5.6 kJ/mol was found for the metastable nanostructured grains, while an approximate activation energy of 142 kJ/mol was found above the restructuring temperature.

Epitaxial 3C–SiC films were grown by chemical vapor deposition on the silicon-on-insulator (SOI) substrates with 20–75-nm-thick Si top layers. A relatively low growth temperature of 1150 °C and a reduced hydrogen flow rate of 1 lpm during the precarbonization process was necessary to preserve the SOI structure and thereby obtain high-quality SiC films. The transmission electron microscopy observation of the SiC/SOI structures revealed high density of misfit dislocations in the SiC film, but no dislocation within the top Si layer. The x-ray-diffraction results did not show any significant shift of the (400) SiC peak position among the SiC/Si and the SiC/SOI samples. This strongly suggests that the Si top layer is not deformed during the SiC/SOI growth and the strain within the 3C–SiC layer is not critically affected by substituting the Si substrate with the SOI substrate, even when the Si top layer is as thin as 20 nm.

Combustion synthesis of Al2O3–TiC–ZrO2 nanoceramics by reactions in the TiO2–Al–C–ZrO2 system is a new method with advantages of simplicity and efficiency. In this work, the effect of ZrO2 nanoparticles on the thermodynamics of combustion synthesis of the TiO2–Al–C system is studied to obtain desired phases. The result of thermodynamic analysis shows that the adiabatic temperature Tad of the system stays at about 2327 K (the melting point of Al2O3) with the addition of ZrO2in the range of 0–15 wt% and the fraction of molten Al2O3 varied from 100% to 78%. The possible combustion products are discussed with an approach of an overlapped phase stability diagram of the Al–O–N, Ti–O–N, Zr–O–N, and C–O–N systems at 2300 K. It has been shown that the combustion product is a mixture of Al2O3–TiC–ZrO2, which coincides with the results obtained by x-ray diffraction and transmission electron microscopy.

On the basis of the first principle interatomic potentials, the site preference of various alloying elements in Fe3Al were evaluated for Ti, Si, Ni, Mn, Mo, and Cr, respectively. The calculated results of the substitutional distribution were in good agreement with the experimental results. Moreover, the calculated results showed that H atoms in Fe3Al prefer to occupy the Fe-type octahedral interstice on the surface, which resulted in concentration of H atoms on the surface. Cr addition decreased the absorbability of Fe3Al-based alloys for H atoms and the force to drive H atoms segregating to surface. The concentration of H atoms on the surface can be decreased by Cr addition.