A method is described to deposit a securely attached, self-assembled monolayer of octadecyltrichlorosilane (OTS) on the surface of freshly cleaved muscovite mica. Comparison of the infrared methylene spectra with those of closely packed Langmuir-Blodgett films implies that the surface coverage of the OTS films was a fraction 0.8–0.9 that of films formed by Langmuir-Blodgett (LB) methods. However, LB monolayers are less securely attached to the substrate. The contact angle of water on these self-assembled monolayers remained over 100° for over 24 h and it suffered no noticeable degradation after prolonged reflux in cyclohexane. The method to form an OTS monolayer on mica involves three steps; first, ion exchange of the native K+ ions of cleaved mica for H+ ions; second, control of the quantity of resulting water on the mica surface; third, adsorption and surface polymerization of octadecyltrichlorosilane (OTS) by self-assembly from dilute cyclohexane solution.

We have studied the crystal structure and the dielectric properties of a scries of Bi-based ceramic compositions as a function of compositional variation and sintering temperature. These dielectrics have dielectric constants hetween 70 and 165 and their temperature coefficients are within ±500 × 10−6/°C. The precise temperature coefficient can be controlled via compositional changes such that dielectrics with temperature coefficients within ±50 × 10−6/°C are easily obtainable. The room temperature dissipation factor is smaller than 0.001 or equivalently, the Q value is greater than 1000. The electrical resistivity is greater than 1014 ohm-cm. Furthermore, these dielectrics are sinterable below 960 °C, rendering it possible to use silver or high silver metallization as the internal electrode in making the multilayer ceramic capacitors.

The oxygen-related defect in an aluminum nitride (AIN) single crystal and in polycrystalline ceramics is investigated utilizing photoluminescence spectroscopy, thermal conductivity measurements, x-ray diffraction lattice parameter measurements, and transmission electron microscopy. The results of these measurements indicate that at oxygen concentrations near 0.75 at.%, a transition in the oxygen accommodating defect occurs. On both sides of this transition, simple structural models for the oxygen defect are proposed and shown to be in good agreement with the thermal conductivity and lattice parameter measurements, and to be consistent with the formation of various extended defects (e.g., inversion domain boundaries) at higher oxygen concentrations.

The fracture toughness of a macro-defect-free (MDF) cement was calculated from two measurement techniques: (1) indentation-strength method and (2) fracture surface analysis (FSA). It was found that the indentation-strength method, which showed good agreement with FSA, was applicable for estimating the fracture toughness of MDF cement. The ultimate toughness was found to be 1.25 MPa m1/2 for this MDF cement, which contained 3 wt. % polymer. An R-curve (crack-growth-resistance) bchavior was also observed. Scanning electron micrographs showed extensive microcracking on the fracture surface. Microstructural effects are discussed.