Low-temperature transport properties of Zn4Sb3 bulk crystal grown by gradient freeze method

The low temperature thermoelectric properties have been investigated on Zn₄Sb₃ compound between 4 K and 300 K. A single phase Zn₄Sb₃ bulk crystal with the density of 95.4% of the theoretical has been grown by a gradient freeze method. The resistivity exhibits a metallic conduction with an anomaly associated with a structural transformation from α to β phase at T_S^GF=257.4 K. The thermopower is positive and larger in α than in β phase. The elongation of Zn₄Sb₃ is small (1×10^-4) at T_S^GF. The magnetic measurement shows that Zn₄ Sb₃ exhibits diamagnetism and χ(T) curve has an appreciable increase at T_S^GF. The power factor of a phase is two times as large as that of β phase at low-temperature region (below 300 K)