High‐Temperature Electrical Transport Behavior Observed in the La1.96M0.04CuO4 (M: Mg, Ca, Sr) Polycrystalline Ceramics

We prepared high‐density La 1.96 M 0.04 CuO 4 (M: Mg, Ca, Sr) polycrystalline ceramics by a spark plasma sintering method, and investigated the temperature dependence of the electrical conductivity, Seebeck coefficient, and power factor. Our results indicate that the relative density of these sintered ceramic samples can reach nearly 100%, and alkaline earth metal ions doping can increase the activation energy (from 0.021 to 0.128 eV). All ceramic samples show high positive Seebeck coefficient (∼100–510 μV/K). The obtained Sr‐doped La 2 CuO 4 ceramics show better thermoelectric properties, which potentially make them for thermoelectric applications.