(color online) Thermoelectric properties of the polycrystalline along the orientation perpendicular to the pressing direction of SPS process: (a) electrical resistivity, (b) Seebeck coefficient, (c) power factor, (d) thermal diffusivity, (e) thermal conductivity ( κT) , and (f) zT. The inset in panel (e) is the lattice thermal conductivity ( κl) , which is calculated based on κl=κT−κe . The carrier thermal conductivity ( κe) is estimated based on the Wiedemann–Franz law ( κe=LσT ). The Lorenz number is derived from Fermi energy with a simple one-band model and only acoustic phonon scattering considered.