Pb对Bi-Sb基纳米热电材料低温性能影响

Effect of Pb on the low temperature thermoelectric properties of Bi-Sb alloy

采用机械合金化法获得Bi0.85Sb0.15-xPbx（其中X=0、0．01、0．03、0．05）纳米晶粉末材料，在常温下用1GPa压制成型，然后在473K温度下烧结2h制成块材，并对其热电性能进行了研究。在80-300K温区测量了样品的Seebeck系数和电导率，并计算出材料在80-300K温区的功率因子变化情况。结果表明：掺入Pb后材料由n型变为P型，在205KBi0.85Sb0.14Pb0.01样品的Seebeck系数为101μV／K，在80-180K掺入少量Pb样品的电导率和功率因子比没掺Pb样品要高，表明掺入Pb可以明显改变Bi0.85Sb0.15纳米晶粉末材料在低温下的热电性能。

The nanocrystallite powders with the formula of Bi0.85Sb0.15-xPbx（x=0, 0.01, 0.03 and 0.05） were perpared by mechanical alloying, pressed under 1GPa at normal room temperature and then pressureless sintered 2h to form bulk samples at 473K. Thermoelectric properties, including Seebeck coefficients and electrical conductivities were measured in the temperature range of 80-300K. The power factor was calculated from Seebeck coefficients and electrical conductivities. The results show that the samples turn into p-type semiconductors from n-type. The Seebeck coefficient of Bi0.85Sb0.14Pb0.01 is 101μV/K at 205K and electrical conductivity is lower than that of Bi0.85Sb0.15. The power factors of the samples with Pb doping are larger than that of the sample without doping. It is suggested that the thermoelectric properties of nanocrystallite Bi0.85Sb0.15 can be improved by doping Pb.