Reactive rf-magnetron sputtering has been employed for the growth of thin films of InN on the (001) face of mica at a variety of substrate temperatures from 50 to 550 °C. These films have been characterized by x-ray scattering, stylus profilometry, and electrical transport measurements, and their topography has been studied by SEM and STM. At low deposition temperatures, the InN films exhibit texture [(00.1)InN‖ (001)mica], while at higher deposition temperatures a large fraction of the grains are heteroepitaxial [(00.1)InN‖(001)mica, (2.0)InN · (060)mica]. The utility of the x-ray precession method in the determination of this heteroepitaxial relationship is highlighted. The films exhibit a local mobility maximum near a substrate temperature of 350 °C, beyond which a sharp increase in resistivity associated with voids and cracks owing to the onset of secondary grain growth leads to a dramatic decrease in electrical mobility. At the highest growth temperatures, however, the interconnection between grains improves and lower resistivity and higher mobility are re-established.

A relaxor ferroelectric of composition 0.93Pb(Mg1/3Nb2/3)O3-0.07PbTiO3 was sintered with 3 wt.% commercial sealing glass at 750 °C for 30 min to achieve ≥95% of theoretical density and a nearly pure perovskite phase. At higher glass additions (up to 20 wt.%), higher sintering temperatures (up to 800 °C), and longer sintering times (up to 4 h), the amount of perovskite (PMN type) decreases and that of pyrochlore (6PbO · MgO · 3Nb2O5 or 3PbO · 2Nb2O5) increases. On sintering at 800 °C for 4 h no perovskite phase is present in compositions with even 1% glass addition. The reaction of glass with the PMN phase was found to lead to the disappearance of the perovskite. Addition of 0.1 to 0.6 wt.% MgO to compositions containing 1 and 3 wt.% glass (and balance PMN-PT) results in essentially pure PMN perovskite phase on sintering at 700–800 °C for 30–240 min, confirming that the reaction of glass with PMN and depletion of MgO from PMN can be arrested. The sintered ceramics exhibit relaxor behavior and possess dielectric properties essentially commensurate with the phase composition.

The structure of amorphous tungsten trioxide films was investigated with IR and Raman spectroscopic analyses and an XRD method. The films were prepared by ion exchange from sodium tungstate as a starting material. Films consisted of microclusters of 10–30 Å diameter, in which the networks are formed with WO6 octahedra sharing their corners and edges. The networks in the as-prepared samples consisted of WO6 units with low symmetry, in which termination by W=O and W—OH2 groups was common. As the post-annealed temperature became higher, the symmetry of WO6 was improved and the edge-sharing octahedra disappeared.

Ion irradiations of the rare-earth orthosilicate, Ca2Nd8(SiO4)6O2, have been carried out using both alpha particles (emitted from a 238PuO2 source) and 3 MeV argon ions. The unit cell exhibits anisotropic expansion under irradiation, consistent with expectations based on the polyhedral connectivity within the structure. A least-squares analysis of the interatomic distances suggests that the unit-cell expansions are primarily due to changes in oxygen-oxygen distances and cation separations between neighboring polyhedra rather than to bonds within polyhedra. The irradiation-induced change in unit-cell volume is proportional to 1 – exp (BD), where B is an annealing rate constant and D is the dose, in agreement with a model for the accumulation of isolated point defects in the structure. The volume expansion saturates at 2.56% and 1.40% for the alpha and argon irradiations, respectively. Analysis of the results suggests that a significant fraction of the defects produced in the argon-ion displacement cascades are lost to in-cascade recombination. Differential scanning calorimetry of powder irradiated with 3 MeV argon ions to 20 ions/nm2 reveals an exothermic recovery peak at 350 °C with an activation energy of 1.3 ± 0.1 eV and average stored energy release of 28.2 J/g. There is no evidence for amorphization of this material under alpha or argon irradiation.

Isothermal capacitance transient spectroscopy measurements were performed to study the reoxidizing induced change in interface states in (Sr, Ca)TiO3−x based ceramics. A discrete acceptor type trap level was detected with reoxidation below the oxidation temperature of grain surfaces, but two deep levels were detected with reoxidation above this temperature. These ICTS results are in good agreement with the previous report with the DLTS measurements. These interface states are considered to originate from chemisorbed oxygen (O2−, O−) on grain surfaces. The O− and O2− chemisorption levels contribute to the non-ohmic conduction with reoxidizing anneals below and above the oxidation temperature, respectively.

We have examined the effect of excimer laser surface processing and doping with Au on the mechanical, tribological, and bonding properties of MoSx thin films. We find that the effects of processing are manifested primarily in the surface of the films, but that there is also some film-substrate interaction during high fluence processing. The changes are sufficient to dramatically alter the wear life of the films. At low loads, laser processing alone reduces the run-in period and increases wear life. At higher loads, processing reduces wear life, although the run-in period is still short. These results are understood in terms of changes in the hardness of the surface of the films. Laser processing renders deposited films insensitive to high humidity storage. After laser processing, Raman spectroscopy shows changes in bonding to that characteristic of single crystal MoS2. Laser doping with Au results in wear life comparable to or greater than that of unprocessed films even at the highest loads used. Thus, laser doped MoSx films show lower initial friction, comparable wear life, and may exhibit greater environmental stability than as-deposited films.

Measurements of atomic Na emission accompanying the fracture of sodium trisilicate glass and a soda lime glass in vacuum were made by quadrupole mass spectroscopy and surface ionization techniques. Peak Na° emission intensities occur some 3–6 ms after the fracture event and decay over tens of milliseconds. This behavior is attributed to the diffusion of Na+ ions into a layer of damaged material at the surface where the ions are subsequently neutralized and thermally emitted as Na°. Charge carriers generated during fracture and subsequently trapped at defect sites apparently play important roles in charge compensating Na+ diffusion and in neutralizing Na+. During the first 300 ms following fracture, we also observe intense, short lived (400 μs) bursts in Na° emission which may be associated with catastrophic relaxation of residual stresses. The kinetics of Na emission suggest that the relaxation of newly formed glass surfaces involves rather complex surface physical and chemical processes.

A new approach is proposed to analyze the fracture behavior with crack tip plasticity by the use of three independent measurements: E0 is the energy required per unit length of crack front to prepare the crack just before propagation; the Ef-curve is a plot of the energy required to produce a unit area of fractured surface versus the crack length; and the Ka-curve is a plot of the applied stress intensity factor KIapp versus the crack length. For ABS polymers, the prefracture energy E0 is 33 Jm−1; the Ef-curve is a horizontal line of 5.2 × 104 Jm−2; and the Ka curve has three different regions which depend on the development of the plastic zone during fracture.

Solvent induced crazes formed in strained polyimide thin films on different substrates have been studied. A fracture mechanics approach has been used to simulate craze evolution. The experiments and simulations have identified a critical prestrain below which craze formation does not occur. This strain decreases with increase in solvent exposure time, but also exhibits a threshold. Diffusion of the solvent into the film is considered to be responsible for the time-dependent nature of damage formation.