We have found a new route for preparing Pt containing perovskites. Ba containing perovskite powder, (La0.7Sr0.2Ba0.1)ScO3–δ (LSBS), reacted with Pt foil at 1898 K in air, and formed ultramarine colored Pt containing perovskite, (La0.7Sr0.2Ba0.1)(Sc,Pt)O3–δ, without changing the GdFeO3-type structure. The chemical compositions of the samples before and after firing, measured with inductively coupled plasma (ICP) optical emission spectrometry, were La: Sr: Ba: Sc = 0.70(1): 0.206(4): 0.101(2): 0.98(2) and La: Sr: Ba: Sc: Pt = 0.70(1): 0.197(4): 0.085(2): 0.95(2): 0.0062(2), respectively. The reaction proceeded not only at the interface between perovskite powder and Pt foil, but also over whole powder surface. We name this new preparation method the “solid-phase elution (SE) method”, because the process involves elution of Pt ions from the Pt foil to the LSBS perovskite lattice. It is expected that we can control the amount of Pt introduced into perovskites by using the SE method after optimizing the reaction time and temperature.

We report on the one-phonon Raman scattering spectra from the following M2AC MAX-phase ternary carbides: Ti2AlC, V2AlC, Cr2AlC, Nb2AlC, Ta2AlC, Ti2InC, Hf2InC, V2GeC, Cr2GeC, V2AsC, and Nb2AsC. We also report the results of calculations of the Γ-point, Raman-active phonon energies for these phases based on density functional theoretical simulations, including the effect of the k-point sampling on the convergence of phonon energies. Good agreement between all measured and calculated Γ-point Raman-active optical phonon energies is obtained.

We investigated the effect of strain rate on the plastic-flow stress of a Zr-based bulk-metallic glass in quasistatic compression. The results indicate that the plastic-flow stress is dependent on the strain rate: an increase in the strain rate leads to a decrease in the plastic-flow stress, and vice versa. However, simply loading, unloading, and reloading at a constant strain rate do not change the plastic-flow stress. This strain-rate dependence of the plastic-flow stress may be related to shear-banding operations.

A method is introduced to determine the depth distribution of the residual stresses in (Ti,Al)N films. The films were gradually stripped by chemical corrosion, an optical system was designed to test the curvature change of the specimens, and the depth distribution of the residual stresses was calculated. The results show that the residual stresses increase gradually from the interface of film/substrate and reach a maximum value at the middle region, then decrease until the surface.

This study investigates interfacial reactions of (Sn–9Zn) + xCu/Ni systems. Ni5Zn21, Cu5Zn8, (Ni,Zn,Cu)3Sn4, (Cu,Ni,Zn)6Sn5, and Cu6Sn5 phases were formed on the Sn–9Zn/Ni interface at 240–270 °C, when 0–10 wt% Cu was added to the Sn–9Zn solder. Experimental results indicate that changing the concentration of Cu in the Sn–9Zn solder dramatically changes the formation of intermetallic compounds (IMCs) in the (Sn–9Zn) + xCu/Ni system. Different diffusion and segregation rates of elements are the main reasons for a change in the IMC evolution.

N-doped and (Al,N)-codoped ZnO films were synthesized by oxidative annealing of (Zn + Zn3N2) films, which were fabricated by reactive magnetron sputtering. Both n- and p-type conductions were obtained in these ZnO:N and ZnO:AlN films. Optimal oxidation treatments for achieving p-type ZnO are annealing at 400–600 °C for 10–60 min, depending on the film thickness and morphology. The electric properties were found to be very sensitive to the annealing conditions and film structure. As-deposited (Zn + Zn3N2) films with and without Al addition had carrier concentrations of 1021–1022 cm−3. After conversion to ZnO, the n-type films had a carrier concentrations up to 1019 cm−3, whereas the p-type ZnO:N films had hole concentrations of 1014–1016 cm−3. (Al,N)-codoping increased the hole concentration of p-type film to 1018 cm−3 despite a decrease in Hall mobility. The photoluminescence properties of the p-type ZnO films were also investigated. The synthesis of p-type ZnO:AlN by oxidative annealing is believed to provide an alternative approach to realize p-type conduction in codoped ZnO film by using N2 as the N source.

Dielectric response of the perovskite ceramics (1–x)La(Mg1/2Ti1/2)O3–x(Na1/2Bi1/2)TiO3 [(1–x)LMT–xNBT] (0 ⩽ x ⩽ 0.6) has been characterized at radio, microwave, and far infrared frequency ranges. Temperature variations of the dielectric permittivity and loss estimated by different methods were compared and analyzed. It was revealed that the low temperature dielectric response of the compositions with x ⩾ 0.2 is frequency-dependent over a wide range (102–109 Hz) below the resonant frequencies of the polar phonon modes. Contributions of different factors (both extrinsic and intrinsic) to the microwave dielectric loss of the ceramics were considered. The dielectric relaxation has been associated with the amount of bismuth in the system. The relaxation in LMT–NBT was considered in the context of similar effects observed in other Bi-containing, A-site disordered oxygen-octahedral compositions.

Layered ternary T-Al-C ceramics containing early transition metal Sc, Zr, and Hf, crystallize with the TnAl3Cn+2 formula, while others containing neighbor elements Ti, V, Cr, Nb, Mo, W, and Ta yield the Tn+1AlCn formula. Ternary TnAl3Cn+2 ceramics are structurally characterized by NaCl-type TC slabs being separated by Al4C3-type AlC layers. In the present study, we suggest that the ability of forming the TnAl3Cn+2 carbide could be traced back to the structure mismatches between the TC, Al4C3 and TnAl3Cn+2 compounds. Ternary carbides following the TnAl3Cn+2 formula experience small lattice mismatches and strain energies. Moreover, the discrepancy between crystal structures of TnAl3Cn+2 and Tn+1AlCn is interpreted by lattice mismatch and the produced strain energy for the ternary T-Al-C ceramics. We also present close relationships between the atomic radii of transition metal and lattice mismatch, as well as the strain energy. The proposed method is not only helpful to explain the trend in crystal structure of T-Al-C based ceramics, but may be also general to predict the crystal structure of layered compounds constructed by alternatively stacked structural units.

Selective growth of CuO nanowires on the etched face of Al2O3/Cu/Al2O3 thin-film multilayer patterns was achieved by ambient oxidation at 400 °C. The nanowires were observed to selectively grow only from the pattern edge with diameter limited by the thickness of Cu thin film. Transmission-electron-microscopy (TEM) characterization confirmed CuO nanowires of a monoclinic CuO growing in the [010] crystallographic direction. Nanowire growth kinetics was studied at 400 °C for different cumulative growth durations with initial growth rates of ∼1 nm/min. A base growth mechanism with kinetics limited by oxygen diffusion through defects of a scaling oxide film is consistent with observed kinetics. The oxygen diffusivity is found to be ∼10−11 cm2/s, consistent with the grain-boundary diffusion of oxygen through polycrystalline copper oxide.

TiCx–Al2O3 composites have been synthesized by pressure-assisted combustion synthesis of (Ti + C + Al2O3) reactant powder. Different alumina contents (10–40 vol%) have been investigated to study the dilution effect on TiC microstructure. A mechanical method and a mixed chemical/mechanical method have been used to obtain (Ti + C + Al2O3) powder mixtures with different alumina distributions. Scanning electron microscopy (SEM) observations of these mixtures show that alumina is distributed inside micrometric (Ti + C) aggregates for the first method whereas alumina is located around (Ti + C) aggregates for the second one. X-ray diffraction (XRD) and SEM analyses of the composites indicate that TiCx is substoichiometric in carbon and mainly consists of submicrometric grains. A distribution of Al2O3 inside (Ti + C) aggregates is more efficient to reduce TiC grain size. For the 40 vol% Al2O3 diluted (Ti + C) mixture prepared from the mechanical route, TiCx nanocrystallites have been successfully stabilized, which demonstrates that the addition of Al2O3 diluent in a (Ti + C) mixture can be efficiently used to inhibit grain growth.

Based on the synthesis of a sufficient amount of AlN nanowires (AlN-NWs), AlN-NWs/Al composites with homogenously distributed AlN-NWs were fabricated. Microstructural observations reveal that the interface between AlN-NWs and Al matrix is clean and bonded well, and no interfacial reaction product was formed at the nanowire-matrix boundary. Mechanical properties including yield and tensile strength of the composites were improved with AlN-NWs volume fraction changing from 5 to 15 vol%, and the maximum yield and tensile strengths of the composite were about 6 and 5 times, respectively, as high as those of Al matrix. Meanwhile, AlN-NWs effectively decreased the coefficient of thermal expansion (CTE) of the composites, and the CTE of 15 vol% composite was about one half that of Al matrix. The results obtained suggest that AlN nanowire is a promising reinforcement for optimizing the mechanical and thermal properties of metal matrix composites.

Anthracene based nano/microstructures of different sizes and shapes like tubes/fibers are synthesized using a simple open air chemical vapor deposition technique. Thermal solid phase reaction between anthracene 9-carboxylic acid and calcium oxide reported recently [H. Liu et al., J. Am. Chem. Soc.125, 10794 (2003)] is used to obtain organic molecular nanostructures. The products of temperature (320 °C) induced reaction get deposited on the substrates placed inside the reaction chamber as well as on the inner walls in different nano/micrometer forms, tubes/rods/fibers and having different sizes. Structural characterization of the reaction products is performed using optical microscopy, field emission electron microscopy (FE-SEM) and transmission electron microscopy (TEM). Chemical composition studies are conducted using infrared (IR), nuclear magnetic resonance (NMR), and gas chromatography (GC)-Mass spectroscopy, as well as elemental analysis. IR studies of the nanostructures obtained on the substrate using IR spectroscopy reveal the presence of C=O groups, the confirmatory evidence of which is obtained using energy dispersive x-ray spectroscopic (EDS) analysis. Interaction study of the C=O groups with ammonia vapor is conducted and resulting changes are monitored using Fourier transform infrared (FTIR). A strong covalent modification of anthracene based structures by exposure to ammonia molecules is indicated.

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.

Multilayer thin-film materials with various thicknesses, compositions, and deposition methods for each layer typically exhibit residual stresses. In situ transmission electron microscopy (TEM) is a powerful technique that has been used to determine correlations between residual stresses and the microstructure. However, to produce electron transparent specimens for TEM, one or more layers of the film are sacrificed, thus altering the state of stresses. By conducting a stress analysis of multilayer thin-film TEM specimens, using a finite element method, we show that the film stresses can be considerably altered after TEM sample preparation. The stress state depends on the geometry and the interactions among multiple layers.

The influence of the Ti/Ba ratio on the formation of pyroelectric and piezoelectric quasi-amorphous BaTiO3 films was investigated. Three types of films, Ti-rich, Ba-rich, and stoichiometric, were pulled through a temperature gradient or subjected to isothermal heating. The quasi-amorphous polar phase only formed in films pulled through the temperature gradient with Ti/Ba ratio within the broad range of 0.95–1.1. This implies that quasi-amorphous pyroelectric and piezoelectric thin films are significantly more tolerant of a deviation from stoichiometry than their crystalline counterparts.

Two different morphologies of MoS2 (short and long sheets) were utilized to elucidate the intercalation mechanism of 1,2,3,4 tetrahydroquinoline (THQ). MoS2 (short sheets) and molybdenite (MB) (long sheets) were exfoliated and restacked in the presence of THQ. The x-ray diffraction patterns of both samples show a new reflection in the 001 plane, which implies a lowering of symmetry and corresponds to an expansion of the layers by approximately 12.3 Å. In the MoS2-THQ sample, 80% of the MoS2 was intercalated and 20% remained stacked. In the MB-THQ sample, 30% of MB was intercalated while 70% remained stacked. X-ray absorption structure (XAS) studies showed changes in atomic geometry and coordination. The x-ray absorption near-edge spectra showed shifts in the geometry of the intercalated MoS2 and MB sample compared to the unintercalated samples. Extended x-ray absorption fine structure studies showed lower coordination numbers compared to the untreated samples. Infrared spectroscopy characterization of these same samples suggests intercalation and partial dehydrogenation of the THQ.

The interaction of a gliding screw dislocation with stacking fault tetrahedron (SFT) in face-centered cubic (fcc) copper (Cu) was studied using molecular dynamics simulations. Upon intersection, the screw dislocation spontaneously cross slips on the SFT face. One of the cross-slipped Shockley partials glides toward the SFT base, partially absorbing the SFT. At low applied stress, partial absorption produces a superjog, with detachment of the trailing Shockley partial via an Orowan process. This leaves a small perfect SFT and a truncated base behind, which subsequently form a sheared SFT with a pair of opposite sense ledges. At higher applied shear stress, the ledges can self-heal by gliding toward an SFT apex and transform the sheared SFT into a perfect SFT. However, complete absorption or collapse of an SFT (or sheared SFT) by a moving screw dislocation is not observed. These observations provide insights into defect-free channel formation in deformed irradiated Cu.

In this work, formation of diamond coating is studied using large-scale molecular dynamics (MD) simulation. The diamond coating is studied to explore how and to what extent the temperature and pressure affects the deposition structure. To analyze the coating results, the radial distribution function and the fraction of diamond (sp3 bonds) is calculated. It is found that the sp3 fraction in the deposition structure increases with the temperature and pressure. When the pressure becomes large enough (10 GPa), the effect of the pressure on the coating structure is quite small and the sp3 fraction tends to be constant.

Varying amounts of Zn (1, 3, 7 wt%) were added to Sn–3.5Ag solder on the electroless Ni(P)/immersion Au metallization, and solder joint microstructures after reflow and isothermal aging (500 h at 150 °C) were investigated using scanning electron microscopy, energy dispersive x-ray spectroscopy, transmission electron microscopy, and x-ray diffraction, which were subsequently correlated to the microhardness and drop test results. Zinc in the solder affected the solder joint intermetallic compounds profoundly, which improved the drop reliability significantly. The effect of Zn was to nucleate Ni5Zn21 and to suppress the formation of Ni3P, Ni3SnP, and Ni3Sn4, which were known to increase the propensity for brittle cracking. Drop test results showed an inverse correlation between the number of drops-to-failure (Nf) and the thickness of Ni3P layer. As the growth of the Ni3P layer was suppressed by Zn, drop reliability increased substantially.

Langmuir monolayers floating on supersaturated aqueous subphases can act as templates for the growth of oriented inorganic films—a “bioinspired” nucleation process. We have performed in situ grazing incidence x-ray diffraction studies of the selective nucleation of BaClF and BaF2 under fatty acid monolayers. The arrangement of the fatty acid headgroups, the monolayer charge, and ion-specific effects all play important roles in selecting the inorganic species. When the monolayer is in a neutral state, both BaClF and BaF2 nucleate at the interface and are well aligned, but when the monolayer headgroup is deprotonated, only oriented BaF2 grows at the interface. We also observe an enhanced alignment of BaF2 crystals during growth from highly supersaturated solutions, presumably due to reorganization of preformed crystals at the organic template. These results show that a delicate interplay between multiple factors governs the oriented growth of inorganic films at organic templates.