Formation of silicon oxynitride was observed during silicon nitride whisker synthesis from silica, carbon and nitrogen. The silicon oxynitride formation was limited to a bottom area of the charged powders and found both in whisker and powder. The possible reason for this localized Si2N20 formation is analysed, based on the effect of gas phase composition on the phase stability among 13-SiaN4, 1...

A fast and accurate analytical method was established for the simultaneous direct determination of aluminum, calcium and iron in silicon carbide and silicon nitride powders by graphite furnace atomic absorption spectrometry using a slurry sampling technique and a Hitachi Model Z-9000 atomic absorption spectrometer. The slurry samples were prepared by the ultrasonication of silicon carbide or si...

BACKGROUND Polyetheretherketone (PEEK) cages have been widely used in the treatment of lumbar degenerative disc disorders, and show good clinical results. Still, complications such as subsidence and migration of the cage are frequently seen. A lack of osteointegration and fibrous tissues surrounding PEEK cages are held responsible. Ceramic implants made of silicon nitride show better biocompati...

We introduce and present experimental evaluations of loss and nonlinear optical response in a waveguide and an optical resonator, both implemented with a silicon nitride/ silicon dioxide material platform prepared by plasma-enhanced chemical vapor deposition with dual frequency reactors that significantly reduce the stress and the consequent loss of the devices. We measure a relatively small lo...

Dense Silicon nitride was investigated to determine the effect of its microstructural parameters and densification on thermo-mechanical properties and thermal stress resistance to fracture initiation during a hot or cold mechanical and thermal shock testing. The different materials and microstructures were obtained by changing the parameters such as the type of the powder, additive, forming p...

We have built and characterized batch-processed polarization beam splitters (PBS), important optical components to separate the orthogonal TE and TM components of light. The devices were fabricated from thin-film, low-stress silicon nitride membranes and showed excellent performance. By stacking membranes, and a triple-layer PBS produced extinction ratios of 21 and 16dB for reflected and transm...

This paper presents the results of a micromechanical model used to explain the strain-rate dependence of the compression fatigue lives of amorphous and crystalline grain boundary phase; denoted by ABP and CBP silicon nitrides, respectively. When the strain-rate is changed from 400 to 0.01/s, the fatigue lives of both materials, evaluated at a peak stress of 3.2 GPa, increased by more than two o...