Keywords: 
• AgSbTe2 /
• 相稳定 /
• 晶体结构 /
• 热电性能

Abstract: CuxAgl-zSbTe2 samples with x = 0-0.3 are prepared by a combined process of melt-quenclamg and spark plasma smtenng （SPS）. X-ray powder diffraction （XRD） analysis indicates that single phase samples with the NaCl-type structure are obtained for the Cu-doped samples before SPS treatment, whereas a small quantity of AgaTe impurities coexist with the main cubic phase for the sample without Cu. According to our thermoanalysis and XRD results, the substitution of Cu for Ag can effectively prevent the precipitation of AgzTe, but this also leads to the presence of a minor amorphous phase in the melt-quenched sample. The amorphous phase crystallizes into SbTTe metastable phase at about 540 K, which finally transforms into the stable Sb2Te3 compound. After the SPS treatment of the melt-quenched sample, the sample with x = 0.1 remains a single phase with the face-centered-cubic crystal structure, while SbTTe andSb2Tea are precipitated as the second phases for the samples with x = 0.2 and 0.3, respectively. The electrical conductivity increases and the Seebeck coefficient decreases with the addition of Cu due to the existence of the second phase in the samples with x = 0.2 and 0.3. Accordingly, thermal conductivities also increase with the addition of Cu, leading to the reduced thermoelectric performance of the x = 0.2 and 0.3 samples. For the sample with x = 0.1, its power factor is comparable to that of the literature reported AgSbTe2 compound. As a result of so-called alloying effect, the phonon scattering effect is enhanced due to the partial replacement of Ag by Cu, leading to the reduced thermal conductivity of the x = 0.1 sample. Therefore, the CuoaAgo.gSbTe2 sample exhibits the promising thermoelectric performance and a dimensionless thermoelectric figure of merit （ZT） value of 1 is achieved at 620 K.