高压制备 Ag1-x Pb18 SbTe20及其电学性能的研究

摘要

Thermoelectric materials Ag1 -x Pb 1 8 SbTe20 (x =0,0.3,0.6 )were synthesized by high pres-sure method.The composition dependent electrical properties were studied from room temperature to 500 ℃.The result of X-ray diffraction indicates that Ag1 -x Pb 1 8 SbTe20 samples have the structure of NaCl crystal.As Ag content decreases,the lattice constant decreases.The measurement results of elec-trical properties show that the electrical conductivity of Ag1 -x Pb 1 8 SbTe20 samples synthesized by high pressure is much higher than that of other preparing methods.The electrical conductivity increases with x ,and its maximum value reaches 1 598.4 S/cm at room temperature for the Ag0.4 Pb 1 8 SbTe20 sample.As the temperature rises,Seebeck coefficient increases and electrical conductivity decreases. The maximum power factor reaches 1.97 mW/(m·K2 )at 300 ℃ for the Ag0.4 Pb 1 8 SbTe20 sample.%采用高压方法制备了 Ag 偏离化学计量比的 Ag1-x Pb18 SbTe 20(x=0,0.3,0.6)样品,研究了 Ag 含量及温度对样品电学输运性能的影响。X 射线衍射测试结果表明,样品具有单相NaCl 结构,晶格常数随 Ag 含量的减少而变小。电学输运性能测试表明：与常规制备方法相比,高压方法制备的 AgPb18 SbTe 20样品的电导率较高；样品电导率随 x 的增大而逐渐增大,x=0.6时,室温条件下的样品电导率高达1598.4 S/cm。随着温度的升高,Seebeck 系数增大,电导率减小。300℃时,Ag0.4 Pb18 SbTe 20样品的功率因子达到最大值,约为1.97 mW/(m·K2)。