STRUCTURAL AND ELECTRICAL PROPERTIES OF SILICON NITRIDE CERAMIC

The effects of structural properties on the d.c. and a.c. electrical properties of different weight gain reaction bonded silicon nitride (RBSN) have been studied in this work. The degree of nitridation is assessed by the ‘weight gain’ of the ceramic, the percentage by which the weight is increased in the nitriding reaction. From X-ray diffraction (XRD) patterns, it is observed that a higher degree of nitradation sample has strong α-silicon nitride peaks. Intensity of α-silicon nitride peaks decreases with decreases weight gain. The higher degrees of nitridation, the samples have less significant Si peak. XRD patterns were recorded to calculate the lattice parameters of RBSN. The lattice parameters for three weight gain RBSN samples are found to be a =b = 7.7727 A, c= 5.6565 A (26% weight gain), a=b= 7.6272 A, c= 5.6374 A (42% weight gain) and a=b=7.6158 A, c= 5.7732 A (58.27% weight gain) and are in good agreement with the reported values from XRD patterns. Porosity (%) and surface morphology was observed by SEM. Keywords: Silicon nitride ceramic; electrical properties; structural properties. DOI: http://dx.doi.org/10.3329/diujst.v7i1.9648 Daffodil International University Journal of Science and Technology Vol.7(1) 2012 50-58