Effect of Oxygen Impurity on Thermal Conduction Rate of Polycrystalline Si₃N₄

Abstract

Herein, the thermophysical properties and microstructures of the densified Si 3 N 4 , which are prepared by using MgO, Y 2 O 3 , and oxygen getter as sintering additives via conventional hot-pressing sintering and followed by postheat treatment, are reported. Herein, it is found out that the sample using 5 mol.% of MgO, 2 mol.% of Y 2 O 3 , and 1.5 mol.% of Nb has the optimized thermal conductivity of 108 W m À1 •K. Furthermore, increased rate of thermal conduction in the range of 10-15% is mainly originated from the decrease in the lattice oxygen contents of the grains in Si 3 N 4 based on electron spin resonance (ESR) analysis.