Thermoelectric and microstructural properties of Pb_0.9−xSn_0.1Ge_xTe compounds prepared by spinodal decomposition

详细信息    查看全文

• 作者：M. S&#xf8 ; ndergaard^a ; M. Christensen^a ; S. Johnsen^a ; C. Stiewe^b ; T. Dasgupta^b ; E. Mueller^b ; B.B. Iversen^a ; ^{bo@chem.au.dk"" rel=""nofollow}
• 关键词：PbTe– ; SnTe– ; GeTe system ; Thermoelectrics ; Nanostructuring ; Spinodal decomposition
• 刊名：Journal of Solid State Chemistry
• 出版年：2011
• 出版时间：May 2011
• 年：2011
• 卷：184
• 期：5
• 页码：1172-1175
• 全文大小：726 K

文摘

Three samples of Pb_0.9−xSn_0.1Ge_xTe with x=0.25, 0.35, 0.6 were prepared by heating the mixtures above the melting point of the constituent elements followed by quenching in water. The x=0.6 sample is close to the center of the immiscibility region, while the x=0.25 and 0.35 samples are in the Pb rich region inside the spinodal miscibility gap. Microstructural investigations using Powder X-ray Diffraction, Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy revealed both GeTe-rich and PbTe-rich phases. The samples were uniaxially hot pressed and the thermoelectric properties were characterized in the temperature range 2–400 K using a commercial apparatus and from 300 to 650 K with a custom designed setup. The best sample (x=0.6) reached zT≈0.6 at 650 K, while the x=0.25 and 0.35 samples showed thermal instability at elevated temperatures.