Extreme solid state refrigeration using nanostructured Bi-Te alloys.

Lima Sharma, Ana L. (San Jose State University, San Jose, CA) ; Spataru, Dan Catalin ; Medlin, Douglas L. ; Sharma, Peter Anand ; Morales, Alfredo Martin

Sandia National Laboratories

关键词: Alloys;    Transport;    36 Materials Science;    Monocrystals;    Crystal Growth;   

DOI  :  10.2172/993612
RP-ID  :  SAND2009-5978
RP-ID  :  AC04-94AL85000
RP-ID  :  993612

美国|英语

来源: UNT Digital Library

【 摘 要 】

Materials are desperately needed for cryogenic solid state refrigeration. We have investigated nanostructured Bi-Te alloys for their potential use in Ettingshausen refrigeration to liquid nitrogen temperatures. These alloys form alternating layers of Bi{sub 2} and Bi{sub 2}Te{sub 3} blocks in equilibrium. The composition Bi{sub 4}Te{sub 3} was identified as having the greatest potential for having a high Ettingshausen figure of merit. Both single crystal and polycrystalline forms of this material were synthesized. After evaluating the Ettingshausen figure of merit for a large, high quality polycrystal, we simulated the limits of practical refrigeration in this material from 200 to 77 K using a simple device model. The band structure was also computed and compared to experiments. We discuss the crystal growth, transport physics, and practical refrigeration potential of Bi-Te alloys.