Thermoelectric properties of silicon and nickel double doped silicon carbide based sintered

Thermoelectric properties and electrical transport parameters of the Si and Ni co-doped SiC have been studied as functions of both Si and Ni doping concentration and temperature. It is intended to increase the figure of merit easily by addition of isoelectric element Si and transition metal element Ni. The samples were fabricated by conventional wet mixing and powder sintering process. Measurements of electrical resistivity and thermoelectric power were made in the temperature range from room temperature to around 1000 K in He atmosphere. Thermal conductivity were measured in the temperature range from room temperature to around 600 K in air. Measurements of Hall coefficient, X-ray crystallography and EPMA were also made. The thermoelectric power increases drastically by addition of Si and Ni. The maximum value of thermoelectric power reached to about 600 μV. Thermal conductivity reached to the minimum value of 8.0 W/(mK) at 40.0 mass% of Si concentration and 1.0 mass% of Ni concentration. Enhancement of the figure of merit Z was achieved by co-doping of Si and Ni. The figure of merit Z reached to the maximum value of 2.5×10-4K-1.