Transparent polycrystalline cubic silicon nitride

Transparent polycrystalline cubic silicon nitride

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...

Transparent polycrystalline cubic spinels protect and defend

T he first reported work on transparent polycrystalline ceramics goes back to the 1950s. For example, some of the literature on materials discussed in this article, magnesium aluminate spinel and aluminum oxynitride spinels, traces back to late 1950s and early 1960s.1–3 The advantages of these materials over current state-of-the-art materials include • Ease of manufacturing; • Superior mechanic...

Compressibility and thermal expansion of cubic silicon nitride

Photoluminescence and electronic transitions in cubic silicon nitride.

A spectroscopic study of cubic silicon nitride (γ-Si3N4) at cryogenic temperatures of 8 K in the near IR - VUV range of spectra with synchrotron radiation excitation provided the first experimental evidence of direct electronic transitions in this material. The observed photoluminescence (PL) bands were assigned to excitons and excited and centers formed after the electron capture by neutral st...

Pattern Photoresist Silicon Silicon Nitride Silicon Photoresist Silicon Nitride Silicon Etch Nitride Remove Photoresist

In this proposal we seek to establish a porous silicon based etching process in the WTC microfabrication laboratory. The new process will allow us to etch high aspect ratio holes through a wafer. Holes like these are important for decreasing the dead volume of connections between micro and macro systems and for increasing the complexity of micro-fluidic systems. At the present time, the minimum...