Transport properties and thermal behavior of YbMnSb2 semimetal above room temperature

Single crystals of ytterbium manganese diantimonide, YbMnSb2 have been grown from a high-temperature reaction of the elements, employing molten Sb as self-flux. This phase crystallizes in the tetragonal centrosymmetric space group P4/nmm (No. 129) and adopts the ZrCuSiAs structure type. Here, the structure consists of Sb-based square nets and PbO-type layers formed by fused [MnSb4/4] tetrahedra. YbMnSb2 is stable under ambient atmosphere and incongruently melts at a temperature of ca. 1120 K. In the temperature range from 300 K to 450 K, the electrical resistivity of the as-grown single-crystalline material is as low as 3.2 mΩ cm, while its thermopower is as high as 180 μV/K. As such, YbMnSb2 shows promise for thermoelectric applications in the mid-temperature region, with an estimated power factor of 0.85–0.95 mW/(m K2).