Glasses and single crystals have traditionally been used as optical windows. Recently, there has been a high demand for harder and tougher optical windows that are able to endure severe conditions. Transparent polycrystalline ceramics can fulfill this demand because of their superior mechanical properties. It is known that polycrystalline ceramics with a spinel structure in compositions of MgAl...

To improve the spatial resolution of solid-state nanopores, thinning the membrane is a very important issue. The most commonly used membrane material for solid-state nanopores is silicon nitride (Si3N4). However, until now, stable wafer-scale fabrication of Si3N4 membranes with a thickness of less than 5 nm has not been reported, although a further reduction in thickness is desired to improve s...

In this paper, partial transient liquid phase (PTLP) diffusion bonding between Si3N4 ceramics and Ht250 cast iron was carried out by using an Ti/Cu/Kovar/Cu/Ti interlayer. The effects of the heating temperature holding time on microstructure, formation mechanism, mechanical properties Si3N4/Ht250 joints were studied. results show that maximum shear strength joint is 112 MPa when welding 1000 °C...

The nanoparticle technologies consisting of multiple layers of mixtures of activated carbon and ruthenium (IV) oxide for super capacitors are reported. The mono-particulate layer process described here is a modified Langmuir-Blodgett trough. We report the processes for a spray-coated zinc nanopowder electrode used as a counter-electrode forming a galvanic cell of extremely high charge storage c...

Gate-leakage reduction is the key motivation for the replacement of SiO2 with alternative gate dielectrics. 45nm gate length scaled grooved and bulk nMOSFETs are evaluated to bring out the most compatible and power saving dielectric option using Si3N4 and SiO2 using Silvaco ATLAS device simulator. At the scaled thickness, SiO2 controls the leakage better than Si3N4, whereas at increased thickne...

Several methods have been employed to synthesize SiC nanowires. The methods include heating silica gel or fumed silica with activated carbon in a reducing atmosphere, the carbon particles being produced in situ in one of the methods. The simplest method to obtain b-SiC nanowires involves heating silica gel with activated carbon at 1360 uC in H2 or NH3. The same reaction, if carried out in the p...

Thin silicon nitride (Si3N4) films deposited using plasma-enhanced chemical deposition (PECVD) method have been used as metalinsulator-metal (MIM) capacitor dielectric for GaAs heterojunction bipolar transistor (HBT) technology. The characteristics of the films, which were deposited at 300C, were found to be dependent on how the PECVD film was deposited. A silicon nitride film deposited as a mu...

An investigation of the thermal expansion behavior of ceramic fibrous monoliths (FMs) is presented. The emphasis is on the development and validation of material models applicable to Si3N4/BN FMs in both unidirectional and cross-ply architectures. Approximate analytical models are developed for the coefficient of thermal expansion (CTE) based on the analysis of representative unit cells of the ...

A variety of superhard coatings with Vickers plastic hardness exceeding 40 GPa have been reported by several research groups during the last five years (for recent reviews see refs [1,2]). However, one has to distinguish between superhard nanocomposites, such as nc-TiN/a-Si3N4, nc-TiN/a-Si3N4/aand nc-TiSi2, nc-(Ti1-xAlx)N/a-Si3N4, nc-TiN/TiB2, ncTiN/BN, etc. where the high hardness originates f...

Amorphous Si–(B–)C–N polymer-derived ceramics (PDCs) with a boron contentranging from 0 to 8.3 at.% were synthesized by thermolysis of the boron-modifiedpoly(methylvinylsilazane). Correlation of the boron content and the thermal stability ofthese materials in the course of annealing were investigated using high temperaturethermal gravimetric analysis (HT-TGA). Furthermore, t...