Thermoelectric Transport Properties Of The Van Der Waals-Type Layered Rhombohedral Snas-Based Compound, Eusn2as2

The thermoelectric transport properties of the van der Waals-type layered rhombohedral SnAs-based compound, EuSn2As2, have been investigated. A densified polycrystalline sample of EuSn2As2 with porosity () of 2.4(9) vol.% exhibited a weak orientation to the c-axis for hexagonal coordination system; the weak orientation is parallel (P-parallel to) to the pressing direction of hot pressing. Measurements of electrical resistivity (rho), Seebeck coefficient (S), and thermal conductivity (kappa) were conducted perpendicular (P) to the pressing direction. The experimental values of rho and S exhibit metallic temperature dependence and p-type carrier polarity. The power factor (P) was 0.51(8) mW m(-1) K-2 at 673(4) K. Using the Wiedemann-Franz-Lorenz law, the phonon thermal conductivity (kappa(ph)) was estimated to be 0.4(6) W m(-1) K-1 at 673(6) K. The dimensionless figure of merit, ZT, was 0.092(17) at 673(3) K.