Low-temperature transport properties of Zn/sub 4/Sb/sub 3/ bulk crystal grown by gradient freeze method

The low temperature thermoelectric properties have been investigated on Zn/sub 4/Sb/sub 3/ compound between 4 K and 300 K. A single phase Zn/sub 4/Sb/sub 3/ 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 /spl alpha/ to /spl beta/ phase at T/sub S//sup GF/=257.4 K. The thermopower is positive and larger in /spl alpha/ than in /spl beta/ phase. The elongation of Zn/sub 4/Sb/sub 3/ is small (1/spl times/10/sup -4/) at T/sub S//sup GF/. The magnetic measurement shows that Zn/sub 4/Sb/sub 3/ exhibits diamagnetism and /spl chi/(T) curve has an appreciable increase at T/sub S//sup GF/. The power factor of a phase is two times as large as that of /spl beta/ phase at low-temperature region (below 300 K).