Ceramics-Silikáty 54 (3) 263-268 (2010)

ELECTRICAL AND DIELECTRIC PROPERTIES OF MgO–Y₂O₃–Si₃N₄ SINTERED CERAMICS

I. Khan , N. Musahwar , M. Zulfequar

We discussed the effect of composition of Silicon Nitride/yttrium oxide with Magnesium oxide on the electrical and dielectric properties of sintered ceramics. A constant amount of MgO was added to different concentrations of Si₃N₄ and Y₂O₃. It is found that the dc conductivity is thermal activated process in the high temperature range and the activation energy is composition dependent. The variation of dc conductivity with the concentration of Si₃N₄/Y₂O₃ is explained .The permittivity and conductivity representation has also been employed to study temperature and frequency dependence of the ac response. Microstructure, compositional porosity and morphology were also investigated by Scanning Electron Microscope (SEM) and X-rd. As the Si₃N₄/Y₂O₃ concentrations increases the sintered ceramics based composite becomes denser. These types of samples can be used as a high temperature semiconducting materials.

Keywords: Ceramics, Silicon Nitride, Electrical and Dielectric properties, XRD and SEM