Electrically conductive SiC ceramics processed by pressureless sintering

摘要

Polycrystalline SiC ceramics with 10 vol Y2O3-AlN additives were sintered without any applied pressure at temperatures of 1900-2050 degrees C in nitrogen. The electrical resistivity of the resulting SiC ceramics decreased from 6.5 x 10(1) to 1.9 x 10(-2) Omega.cm as the sintering temperature increased from 1900 to 2050 degrees C. The average grain size increased from 0.68 to 2.34 mu m with increase in sintering temperature. A decrease in the electrical resistivity with increasing sintering temperature was attributed to the grain-growth-induced N-doping in the SiC grains, which is supported by the enhanced carrier density. The electrical conductivity of the SiC ceramic sintered at 2050 degrees C was similar to 53 Omega(-1).cm(-1) at room temperature. This ceramic achieved the highest electrical conductivity among pressureless liquid-phase sintered SiC ceramics.