Giant Thermoelectric Power Factor Anisotropy in PtSb1.4Sn0.6.

We report on the giant anisotropy found in the thermoelectric power factor (S2σ) of marcasite structure-type PtSb1.4Sn0.6 single crystal. PtSb1.4Sn0.6, synthesized using an ambient pressure flux growth method upon mixing Sb and Sn on the same atomic site, is a new phase different from both PtSb2 and PtSn2, which crystallize in the cubic Pa3̅ pyrite and Fm3̅m fluorite unit cell symmetry, respectively. The large difference in S2σ for heat flow applied along different principal directions of the orthorhombic unit cell stems mostly from anisotropic Seebeck coefficients.