Highly conductive SiC ceramics containing Ti2CN

Highly conductive SiC ceramics were fabricated by sintering beta-SiC and TiN powder mixture in N-2 atmosphere. SiC ceramics exhibited decreased electrical resistivity (rho) with increasing TiN content. X-ray diffraction data indicated that the specimens consisted of beta-SiC grains without a detectible secondary phase for low TiN content (<= 2 vol%) but contained a Ti2CN phase as the TiN content increased. The temperature-dependent resistivity rho(T) of specimens revealed semiconductor-like behavior for TiN content up to 10 vol% and metal-like behavior above 20 vol%. For the specimen with TiN content of 15 vol%, rho(T) remained almost constant (2.06 +/- 0.01 x 10(-3) Omega cm) in the 4-300 K range. The resistivity of metal-like specimens were as low as 3.5 x 10(-4) Omega cm for TiN content of 20 vol%. For semiconductor-like specimens, rho(T) was primarily affected by N donors in the beta-SiC grains. Metal-like specimens were primarily affected by metallic Ti2CN clusters. (C) 2013 Elsevier Ltd. All rights reserved.