A single crystal of NdBa2Cu3O7−δ was synthesized by the Top Seeded Solution Growth method (TSSG method). Then, the crystal was heat-treated 500 °C for 400 h and then 340 °C for 200 h in a pure oxygen gas flow. This sample showed critical current density (Jc) as high as 15,000 A/cm2 under a magnetic field, of 5 T, applied along the c-axis of the crystal. Electron microscopic studies with energy dispersive x-ray spectroscopy (EDS) have revealed that the Ba/Nd ratio fluctuates between 2.0 and 0.7 with a wavelength of a few tens of nanometer. This implies that superconducting phase of Nd1.0Ba2.0Cu3O7−δ and nonsuperconducting phase of Nd1.8Ba1.2Cu3O7−δ mingle with each other, which is the ideal structure for high-Jc superconducting material.

Internal friction and Mössbauer techniques have been used to investigate the structure of C–Cr associates and the arrangement of Fe atoms near them in the Cr martensitic steel MANET subjected to different thermal treatments. After slow rate cooling from the austenitic field, the Mössbauer spectra exhibit, besides the complex magnetic pattern of martensite, a low intensity singlet attributed to the presence of a Cr-rich bcc phase. In correspondence, the internal friction curves, show, among others, a Snoek-type peak due to anelastic processes involving C–Cr associates with 6 Cr atoms. To explain the experimental results, a simple structural model is suggested.

Planar defects were observed in a hot isostatically pressed Al–Cu–Fe alloy. The defects were determined to be perpendicular to the fivefold direction. They were also found to be regions where the quasiperiodicity in the five-fold direction was disrupted, resulting in a periodicity along this direction of 1.06 nm. The defects were stable up to approximately 750 °C. The defects were determined to be formed by the applied shear forces associated with the consolidation process. The displacement vector of the defects was determined to be in a twofold direction perpendicular to the periodic direction.

We demonstrate that the formation temperature of the C54 TiSi2 phase from the bilayer reaction of Ti on Si is lowered by approximately 100 °C by placing an interfacial layer of Mo or W between Ti and Si. Upon annealing above 500 °C, the C49 TiSi2 phase forms first, as in the reaction of Ti directly on Si. However, the temperature range over which the C49 phase is stable is decreased by approximately 100 °C, allowing C54 TiSi2 formation below 700 °C. Patterned submicron lines (0.25−1.0 μm wide) fabricated without the Mo layer contain only the C49 TiSi2 phase after annealing to 700 °C for 30 s. With a Mo layer less than 3 nm thick between Ti and Si, however, a mixture of C49 and C54 TiSi2 was formed, resulting in a lower resistivity. The enhanced formation of the C54 TiSi2 is attributed to an increased density of nucleation sites for the C49-C54 phase transformation, arising from a finer grained precursor C49 phase.

Deep trapping levels in Bi12TiO20 obtained by top seeded solution growth and by the hydrothermal technique have been compared. This was undertaken as such levels directly influence the photorefractive behavior of the material. It is found that the most predominant of the peaks revealed by thermally stimulated conductivity measurements represents two rather than a single defect level and that the deeper of the two becomes more significant in hydrothermally grown material. One defect found in the solution pulled material is notably absent from that produced hydrothermally. The consequence of adding phosphorus doping and the manner in which it affects the deep levels has also been examined.

A theoretical computation of vibrational anharmonicity is presented which is a generalization of the simple Gruneisen approach. The calculation was based on a model that defines a simple relationship between the binding energy of a solid and the variation of vibration frequencies with volume. The agreement between calculated and experimental Gruneisen constants is good.

It was demonstrated that molten Pd40.5Ni40.5P19 undergoes liquid state phase separation in the undercooling regime δT = T1 − T where T1 is the liquidus of Pd40.5Ni40.5P19 and T is the kinetic crystallization temperature. Liquid state phase separation by nucleation and growth takes place for δT ≤ 60 K while that by spinodal decomposition occurs for δT ≥ 100 K. Microstructural analysis of the undercooled specimen obtained in the undercooling regime of 60 ≤ δT ≤ 100 K indicates that it is the transition regime. Finally, it was found that when undercooled molten Pd40.5Ni40.5P19 undergoes liquid state spinodal decomposition, it first decomposes into two liquid networks, which is finally replaced by a system of three liquid networks.

Using x-ray Rietveld analysis the fcc (fluorite-type) structure of a Na-containing nanocrystalline zirconia powder (9.5 nm estimated crystallite size) obtained by precipitation and calcination has been confirmed. The result shows that conventional x-ray diffraction techniques can distinguish the cubic crystallographic form of ZrO2 from the tetragonal one in nanosized powders. These conclusions are supported by independent Raman scattering experiments.

We report here on the synthesis of large crystals of Si-containing carbon nitride, consisting of a predominantly C–N network, by microwave CVD. The Si content in this material varies from crystal to crystal and also with the deposition conditions and has been observed to be as low as less than 5 at.% in some crystals, wherein the Si atoms are believed to substitute for some of the C sites only. This is the first time that such large and well-faceted crystals consisting almost entirely of carbon-nitride network have been synthesized. Moreover, there is no obvious deposition of amorphous CN material.

A new varistor composition based on SnO2 doped with Co, Al, and Nb has been successfully synthesized by a chemical route. It exhibits excellent nonlinear current-voltage (I-V) characteristics with α ≈ 72 and E1mA ≈ 1820 V/mm.

Fourier transform infrared (FTIR) spectroscopy analysis of SCS-6 silicon carbide fibers was performed to detect the presence of oxygen in the form of SiO2. The results showed infrared peaks corresponding to SiC fundamental lattice absorption as well as reflection. No absorption peak due to SiO2 was observed. These results are in agreement with previously reported data indicating low levels of oxygen in this fiber.

The melt of Bi–Sr–Ca–Cu–O (BSCCO) was quenched by splatting using iron plates, resulting in formation of the glassy plates (0.3–0.7 mm thickness). The plates were converted into superconductors by reheating in air. The critical temperature, Tc, depends on the thickness. The change in Tc is discussed in terms of the difference in the amount of oxygen absorption and in crystallization behavior of the glassy plate during the reheating process between the glassy phase in the interior and that around the surface. It was found that high-Tc glass-ceramic thin plates can be prepared by controlling the amount or the rate of oxygen supply.

A melt-textured process that involves the peritectic reaction Y2BaCuO5 + liquid → YBa2Cu3O7−x is the best method to develop bulk YBa2Cu3O7−x superconductors with improved transport and magnetic properties. Up to this point, information regarding cationic stoichiometry in textured samples is rather lacking in the literature. In this work, wavelength dispersive analysis (WDS) at a microscopic level and energy dispersive x-ray analysis (EDX) at a nanoscopic level were used to characterize the chemical composition of YBa2Cu3O7−x textured samples. The melt-textured process generally modifies the sample stoichiometry. Thus, a textured sample composition cannot be directly obtained even from an accurate knowledge of the starting composition. We have shown that WDS can be used to determine the overall composition and therefore the Y2BaCuO5 content in these samples. It is also a powerful method to control chemical homogeneity and to investigate chemical modifications occurring during processing, especially those resulting from interaction between melt and substrate. The exact nature of YBa2Cu3O7−x nucleation and crystallization still presents many unsolved questions. Nanoanalysis allowed us to study Y2BaCuO5 dissolution in the peritectic liquid, and we have confirmed that it takes place exclusively by removing yttrium from Y2BaCuO5 particles. We have also shown the existence of an yttrium-rich liquid phase, i.e., with a higher yttrium concentration that can be deduced from the equilibrium phase diagram. A liquid phase having a composition close to that of YBa2Cu3O7−x can be inferred from this work. This suggests that YBa2Cu3O7−x nucleation and crystallization take place homogeneously from this liquid.

A detailed analysis of Pt/Ti, Pt/TiO2, and Pt/ZrO2 electrodes was carried out to develop a bottom electrode stack for sol-gel derived thin film capacitors. For the Pt/Ti stack, the choice of layer thickness and deposition temperature is found to affect adhesion to the SiO2/Si substrate as well as the extent of hillock formation and Pt–Ti interaction. By using elevated temperature deposition, Pt films close to 1 μm in thickness can be produced with relatively good adhesion and morphological stability using Ti adhesion layers. In addition, Pt films grown on ZrO2 and TiO2 adhesion layers exhibit little morphological change and no degradation in sheet resistance after annealing at 650 °C. However, neither ZrO2 nor TiO2 are as effective as Ti metal in promoting Pt adhesion. Experiments aimed at establishing a correlation between hillock formation and capacitor yield revealed two important results. First, the behavior of Pt/Ti stacks during annealing in air is markedly different from their behavior during PZT film crystallization. Second, preannealing of the Pt/Ti in air prior to PZT film growth actually improves capacitor yield, even though hillock formation occurs during the preannealing treatment. Implications of these results regarding the role of hillocks in controlling capacitor yield are discussed.

A thermochemical analysis is performed in the quaternary system Cu–In–S–O at 298 K, including the respective four ternaries. The Cu–In phase diagram is updated with respect to the new experimental as well as to the new thermochemical results in the literature. Free energies of In6S7, In2.8S4, CuIn2, and Cu2In2O5 have been estimated. Consistent sets of data are used for the calculations of the ternary systems with the program thermo, and the results are used to calculate the quaternary tetrahedron Cu–In–S–O with the program thermoq; the algorithm is given. Twelve quaternary two-phase equilibria have been found. They are used to calculate predominance area diagrams of the quaternary system with the program stadiaq for different oxygen partial pressures. The algorithm of this program is given. From these diagrams it becomes obvious that CuInS2 is unstable in air and even in UHV systems and should react to form In2(SO4)3 and Cu2S at oxygen pressures larger than log p (pascal) = −51.5. The results are useful for research in fields such as oxidation and crystal growth of CuInS2 and for development of processes for producing this compound.

The combined effects of isolation stress, active area size, and SiGe misfit strain on dislocation generation in an advanced SiGe heterojunction bipolar transistor (HBT) process were studied. Eight-inch wafers were patterned with polysilicon-filled deep, and oxide-filled shallow trench isolation similar to that used in IBM's analog SiGe HBT technology. Half of the wafers were subjected to an additional stress-producing oxidation prior to SiGe growth. Si1−xGex films containing 0, 5.5, 9, and 13 at.% Ge were grown epitaxially by ultrahigh vacuum chemical vapor deposition (UHV CVD). The films were of constant thickness with an intrinsic Si cap. Some samples received an additional relaxation anneal following deposition. After the growth and anneal cycles, the dislocation density was determined by transmission electron microscopy (TEM). On nonstressed samples, no dislocations were observed in the device areas, even at Ge concentrations which are not stable to misfit dislocation generation in blanket form. This small area effect has been observed on patterned substrates that do not have functional device isolation. On the stressed-isolation wafers, the compressive stress from the oxidation of the trench sidewalls was found to intensify stress in the SiGe films, and to lower the critical strain at which misfit dislocations appeared. In large active areas on these wafers, two distinct dislocation regions were observed. Defects at the edge resembled those caused by isolation stress, while the defects in the center were more typical of the misfit dislocations associated with lattice-mismatch epitaxial films. It is clear that isolation stress must be minimized when fabricating integrated circuits using SiGe epitaxial films. It is also evident that SiGe films grown on nonstressed isolation exhibit the same increase in critical thickness with decreasing lateral dimension that has been observed on much simpler patterned substrates.

Molten nitrates in the system (1 − x)NaNO3−xBa(NO3)2 were solidified in the presence of a power ultrasound of 20 kHz. Their microstructures were compared with those of controlled samples which were solidified normally. Grain size in the controlled sample of monolithic NaNO3 (x = 0) was reduced by sonication. In the hypo- (x = 8 wt. %) and the hypereutectic (x = 28 wt. %) binary samples, the sonication completely eliminated the dendritic structure of the primary crystals and induced equiaxed particles of the primary phase. At eutectic (x = 18 wt. %), the sonication removed oriented structures of the eutectic lamellae. Several mechanisms of the microstructural modification were mentioned.

The results of high resolution transmission electron microscope (HRTEM) observation and image simulation show that Zr4Co4Si7 possesses the same structure type of Zr4Co4Ge7. Addition of Fe or Ni into the Zr4Co4Si7 compound, except that the dimensions changed slightly, does not change the lattice type and coordination in the crystal structure, maintaining the V-phase structure. Also, twins with coherent boundaries and partially coherent interfaces are observed. The image conditions of Zr4Co4Si7 and the structure differences between Zr4Co4Si7 and tetrahedral close-packed phases are also discussed.

The uniformity and reaction kinetics of ion-beam deposited Al/Ni multilayer samples with the same composition, Al81.8Ni18.2, and modulation wavelength, Λ = 20 nm, but with different total film thicknesses were investigated by x-ray diffraction and differential scanning calorimetry measurements. The total film thicknesses varied between approximately 0.5 and 2.0 μm. It was found that the interface widths were approximately 1 nm and the Ni layers are much more disordered than the Al layers. The thicker samples show an increase in disorder on a length scale comparable to Λ. In other experiments, a change was observed with increasing modulation wavelength from semicoherent interfaces with a low density of misfit dislocations to semicoherent interfaces with a high density of misfit dislocations. The reaction kinetics for forming the Al9Ni2 phase is independent of the sample thickness.

Ca-modified spherical palladium particles were prepared from the mixed solution of Pd(NO3)2 and Ca(NO3)2 by ultrasonic spray pyrolysis. Pure palladium powder and that modified with less than 55 ppm Ca were composed of single crystal particles. However, Ca addition of more than 500 ppm resulted in polycrystalline particles. Crystallite size of the particles decreased with the increase of Ca addition and changed dramatically at the addition of some hundred ppm. Ca additive did not form solid solution with palladium but formed CaPd3O4 on the surface and grain boundary of the particles. 50 ppm−1% of Ca addition significantly reduced the oxidation of palladium powder. More addition of Ca resulted in excess oxidation due to the reaction between palladium and calcium oxide.