Thermoelectric properties of carbide ceramics:a comparative analysis of thermoelectric properties of B₄C, SiC and TiC

Common high-temperature thermoelectric materials' expensive and rare element contents create a need to develop readily available and cost-effective materials such as carbides, as they have naturally abundant constituents, low costs, and good high-temperature performance. Although there are published research results on the thermoelectric properties of B4C and SiC, they vary widely in production and characterization methods, hence the results. To efficiently compare these materials and initiate a starting point for material selection for developing thermoelectric ceramics and composites as alternatives to toxic and costly common high-temperature thermoelectric materials, B4C, SiC, and TiC were spark plasma sintered under similar conditions with different sintering temperatures due to the different characteristics of the materials. Their thermoelectric properties were analyzed between 323 and 923 K and compared. Thermoelectric properties of TiC were investigated in detail for the first time. The results demonstrated that SiC has a high Seebeck coefficient (564.4 mu V/K), low electrical (602.1 S/m), and high thermal conductivity (65.8 W/mK), B4C has high electrical (6974.8 S/m) and low thermal conductivity (12.4 W/mK), and relatively high Seebeck coefficient (269.5 mu V/K). In contrast, TiC has metallic electrical (1.3 x 10(6) S/m) and relatively low thermal conductivities (32.8 W/mK) while a very low Seebeck coefficient (-9.9 mu V/K).