Anomalous effect of vanadium boride seeding on thermoelectric properties of YB22C2N

Abstract Vanadium boride seeded YB 22 C 2 N were synthesized and the thermoelectric properties investigated. YB 22 C 2 N is representative of the series of rare earth borocarbonitrides which is the potential long awaited n-type counterpart to p-type boron carbide. VB 2 seeded samples of YB 22 C 2 N were prepared using VB 2 directly as an initial additive and V 2 O 3 which also results in formation of vanadium diboride in the final product. The resistivity and Seebeck coefficient of samples were measured in the temperature range of 323 K to 1073 K. A dramatic effect of thermal treatment on the Seebeck coefficient of VB 2 seeded samples was observed, and it is indicated that there is possible partial intrinsic doping of vanadium into YB 22 C 2 N. VB 2 is revealed to be a promising additive to improve the thermoelectric properties of YB 22 C 2 N. An enhancement of more than 220% of the maximum absolute value of the Seebeck coefficient was obtained while the resistivity was also reduced considerably.