The Evaluation of TiTe2 as a Diffusion Barrier in the Formation of Low Thermal Conductivity Nanolaminates with Bi2Te3 and Sb2Te3

Clay Mortensen; Paul Zschack; David C. Johnson

doi:10.4028/www.scientific.net/AST.74.38

Paper Titles

Study and Design for High Thermoelectric Properties for Ag_xTe_yTl_z Compound with First Principle Band Calculation
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Effect of Cobalt-Substitution on the Structure and Thermoelectric Properties of Chimney-Ladder Solid Solution (Mn_1-xCo_x)Si_γ (γ~ 1.7)
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Effect of Strontium and Europium Substitutions on Thermoelectric Properties in Silicon-Based Clathrate Compounds
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Thermoelectric Properties of the Heavy Element Doped Heusler Fe₂VAl Alloy Prepared by Powder Metallurgy Technique
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The Evaluation of TiTe₂ as a Diffusion Barrier in the Formation of Low Thermal Conductivity Nanolaminates with Bi₂Te₃ and Sb₂Te₃
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Structural Characterization of Nano-Crystalline Mg₂Si Prepared by Ball Milling
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High-Temperature Transport Properties of Indium Added Cobalt-Antimonide Based Skutterudites Processed by Current Assisted Short-Term Sintering
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Raman Spectroscopy Study on Na_2/3Mn_1-xFe_xO₂ Oxides
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Thermoelectric Iron Oxides
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HomeAdvances in Science and TechnologyAdvances in Science and Technology Vol. 74The Evaluation of TiTe2 as a Diffusion Barrier in...

The Evaluation of TiTe₂ as a Diffusion Barrier in the Formation of Low Thermal Conductivity Nanolaminates with Bi₂Te₃ and Sb₂Te₃

Abstract:

The evolution of designed [(Ti-Te)]x[(Sb-Te)]y, [(Bi-Te)]x[(Sb-Te)]y, [(Ti-Te)]w[(Bi-Te)]x[(Sb-Te)]y and [(Ti-Te)]w[(Bi-Te)]x[(Ti-Te)]y[(Sb-Te)]z precursors were followed as a function of annealing temperature and time using both low and high angle x-ray diffraction techniques to probe the self assembly into nanolaminate materials. The [(Bi-Te)]x[(Sb-Te)]y precursors were found to interdiffuse at low temperatures to form a (BixSb1-x)2Te3 alloy. The [(Ti-Te)]x[(Bi-Te)]y and [(Ti-Te)]x[(Sb-Te)]y precursors formed ordered nanolaminates [{(TiTe2)}1.35]x[Bi2Te3]y and [{(TiTe2)}1.35]x[Sb2Te3]y respectively. The [(Ti-Te)]w[(Bi-Te)]x[(Sb-Te)]x precursors formed [{(TiTe2)}1.35]w[(Bi0.5Sb0.5)2Te3]2x nanolaminates on annealing, as the bismuth and antimony layers interdiffused. Over the range of TiTe2 thicknesses used in [(Ti-Te)]w[(Bi-Te)]x[(Ti-Te)]y[(Sb-Te)]z precursors, Bi and Sb were found to interdiffuse through the 2-4 nm thick Ti-Te layers, resulting in the formation of (BixSb1-x)2Te3 alloy layers as part of the final nanolaminated products. When the Bi-Te and Sb-Te thicknesses were equal in the amorphous precursors, symmetric [{(TiTe2)}1.35]m[(Bi0.5Sb0.5)2Te3]n nanolamiantes were formed. When the thicknesses of Bi-Te and Sb-Te layers were not equal in the amorphous precursor, asymmetric [(TiTe2)1.35]m[(BixSb1-x)2Te3]n[(TiTe2)1.35]m[(BixSb1-x)2Te3]p nanolaminates were formed. These results imply that to form (A)w(B)x(C)y nanolaminates using designed layered precursors all three components must be immiscible. To form (A)x(B)y(A)x(C)z nanolaminates, the components must be immiscible or the precursor to the A component and the A component itself must be an effective interdiffusion barrier preventing B and C from mixing.