کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1606149 1516215 2016 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effect of spark plasma sintering conditions on the thermoelectric properties of (Bi0.25Sb0.75)2Te3 alloys
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فلزات و آلیاژها
پیش نمایش صفحه اول مقاله
Effect of spark plasma sintering conditions on the thermoelectric properties of (Bi0.25Sb0.75)2Te3 alloys
چکیده انگلیسی


• Spark plasma sintering (SPS) is used to synthesize the thermoelectric (Bi0.25Sb0.75)2Te3.
• Liquid phase and volatile element are a key for the microstructure and thermoelectric property.
• Thermoelectric figure-of-merit of 2.9 × 10−3/K is achieved at 500 °C for 30 min.

As a field-assisted technique, spark plasma sintering (SPS) enables densification of specimens in a very short period of time compared to other sintering techniques. For high performance thermoelectric material synthesis, SPS is widely used to fabricate nanograin-structured thermoelectric materials by rapidly densifying the nanopowders suppressing grain growth. However, the microstructural evolution behavior of thermoelectric materials by SPS, another important process during sintering, has been rarely studied. Here, we explore SPS as a tool to control the microstructure by long-time SPS. Using p-type (Bi0.25Sb0.75)2Te3 thermoelectric materials as a model system, we systematically vary SPS temperature and time to understand the correlations between SPS conditions, microstructural evolution, and the thermoelectric properties. Our results show that the relatively low eutectic temperature (∼420 °C) and the existence of volatile tellurium (Te) are critical factors to determine both microstructure and thermoelectric property. In the liquid-phase sintering regime, rapid evaporation of Te leads to a strong dependence of thermoelectric property on SPS time. On the other hand, in the solid-phase sintering regime, there is a weak dependence on SPS time. The optimum thermoelectric figure-of-merit (Z) of 2.93 × 10−3/K is achieved by SPS at 500 °C for 30 min. Our results will provide an insight on the optimization of SPS conditions for materials containing volatile elements with low eutectic temperature.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Alloys and Compounds - Volume 678, 5 September 2016, Pages 396–402
نویسندگان
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