Preparation of nano-sized Bi2Te3 thermoelectric material powders by cryogenic grinding

• Published in: Progress in natural science 2012-06, Vol.22 (3), p.201-206
• Main Author: Xiaozong Chen a, Leifeng Liu b, Yuan Dong a, Lianjun Wang a, Lidong Chen c, Wan Jiang a, a State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, 2999 people of North Road, Shanghai 201620, PR China b Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden c Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050, PR China
• Format: Article
• Language: English
• Subjects: Bi2Te3; breaking; Cryogenic; Cryogenic grinding; grinding; material; Nanoparticles; TE; Thermoelectric; Thermoelectric (TE) material; Two-step; Two-step breaking model
• ISSN: 1002-0071; 1745-5391
• DOI: 10.1016/j.pnsc.2012.04.006

A novel method for rapid preparation of Bi2Te3 nano-sized powders with an average particle size of about 70 nm was developed. A starting powder mixture consisting of Bi2Te3 coarse particles of ～5 mm was ground using cryogenic grinding in the liquid nitrogen. For comparison, the conventional high-energy ball milling was used to prepare the Bi2Te3 nano-sized powders. Sintering properties of as-prepared powders was investigated by spark plasma sintering (SPS). The effects of the preparation procedure on the crystallinity, morphology and structure were examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was found that Bi2Te3 was not transformed into a non-equilibrium amorphous phase or decomposed during the cryogenic grinding process, and as-prepared nano-powders possessed excellent sinterability. This technique might also be applicable to other thermoelectric materials.