Uranium Nitride U2N3 as a novel thermoelectric material

Uranium compounds are potential candidate materials for thermoelectric power generation and applications in environmentally-friendly cooling. In the present study, single phase U2N3 compound synthesized by glow plasma nitriding is reported as a thermoelectric material for the first time. The electrical conductivity is 302 S/cm at 243 K which decreases to 202 S/cm with increasing temperature, indicating the semimetallic behavior. The Seebeck coefficient of U2N3 suggests n-type conduction with the absolute value of 87 μV/K at 243 K and 133 μV/K at 383 K. The strong scattering of conductive electrons by the 5f electrons of uranium near the Fermi level vicinity is considered to attribute to the large Seebeck coefficient. The maximum Power factor is 3.58 μWcm−1K−2 obtained at 383 K, one order of magnitude larger than that of uranium borides.