Reference

Surface acoustic wave propagation in Nb:H at low temperatures

Engebretson, Amy K. Bylsma; Golding, Brage (Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA). Proceedings - IEEE Ultrasonics Symposium, (Vol. 1), 439-502 (English) 1997 Institute of Electrical and Electronics Engineers. CODEN: PIEUEZ. ISSN: 1051-0117. DOCUMENT TYPE: Journal CA Section: 76 (Electric Phenomena) The acoustic properties of evapd. polycryst. There are some commonly used reagents like 12655-93-5 in this article. niobium films have been studied to temps. below 100 mK using surface acoustic waves. The expts. probe the process which occurs when hydrogen atoms tunnel between two nearly degenerate interstitial sites. The interaction of sound with tunneling defects leads to temp.-dependent changes in acoustic absorption and velocity below 10 K. By analyzing the acoustic properties, the authors ext. the tunneling system relaxation rates and their coupling strengths to electrons and phonons. The presence of the superconducting gap below Tc inhibits relaxation through the electronic channel allowing us to sep. electronic and phononic decay paths. .