Electrical and thermal properties of SiC-AlN ceramics without sintering additives

摘要

Ceramics of SiC-AlN, consisting of alpha-SiC (6H and/or 4H) and 2H SiC-AlN solid solution (2H(ss)), were fabricated by conventional hot-pressing in an Ar atmosphere without sintering additives. The electrical resistivities of the SiC-AlN ceramics were 1.9 x 10(6) Omega cm for 2 vol% AlN, 3.7 x 10(9) Omega cm for 10 vol% AlN, and 1.1 x 10(10) Omega cm for 35 vol% AlN, at room temperature. There was an increasing trend in resistivity with increasing AN content which was most likely due to increased Al impurities at Si site acting as deep acceptors for trapping nitrogen-derived carriers. The thermal conductivity of the SiC-AlN ceramics showed a decreasing trend: 104.1 W/m K at 2 vol% AN, 49.8 W/m K at 10 vol% AN, and 35.1 W/m K at 35 vol% AN content, due to increasing 2H(ss) content in the ceramics. There was a trade-off in improving both the thermal conductivity and electrical resistivity in SiC-AlN ceramics. (C) 2015 Elsevier Ltd. All rights reserved.