A simple method for producing high conductivity copper for low temperature applications

✍ Scribed by S.S. Rosenblum; W.A. Steyert; F.R. Fickett

• Publisher: Elsevier Science
• Year: 1977
• Tongue: English
• Weight: 469 KB
• Volume: 17
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(77)90123-0

✦ Synopsis

We report here the details and results of a simple technique for treating polycrystalline copper which significantly reduces its low temperature electrical resistivity (and concomitantly the thermal resistivity). For polycrystalline copper, in the best cases one can obtain residual resistance ratios, rrr, defined as rrr = R ( 2 9 5 K ) / R ( 4 K) ~ p ( 2 9 5 K ) / p ( 4 K) of over 10 000. For copper of electrical quality or better, the room temperature resistivity is completely dominated by the phonon contribution and is independent of the usually small amounts of impurities (less than 30 ppm), thus, the larger the rrr, the better is the copper as a low temperature conductor.