Submillimeter and microwave residual losses in epitaxial films of Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O
- Lawrence Berkeley Lab., CA (United States)
- Conductus, Inc., Sunnyvale, CA (United States)
- Stanford Univ., CA (United States). Dept. of Applied Physics
- Bell Communications Research, Inc., Red Bank, NJ (United States)
- Sandia National Labs., Albuquerque, NM (United States)
- International Business Machines Corp., San Jose, CA (United States)
- Superconductor Technologies, Inc., Santa Barbara, CA (United States)
We have used a novel bolometric technique and a resonant technique to obtain accurate submillimeter and microwave residual loss data for epitaxial thin films of YBa{sub 2}Cu{sub 3}O{sub 7}, Tl{sub 2}Ca{sub 2}Ba{sub 2}Cu{sub 3}O{sub 10} and Tl{sub 2}CaBa{sub 2}Cu{sub 2}O{sub 8}. For all films we obtain good agreement between the submillimeter and microwave data, with the residual losses in both the Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O films scaling approximately as frequency squared below {approximately} 1 THz. We are able to fit the losses in the Y-Ba-Cu-O films to a weakly coupled grain model for the a-b plane conductivity, in good agreement with results from a Kramers-Kronig analysis of the loss data. We observe strong phonon structure in the Tl-Ca-Ba-Cu-O films for frequencies between 2 and 21 THz, and are unable to fit these losses to the simple weakly coupled grain model. This is in strong contrast to the case for other high {Tc} superconductors such as YBa{sub 2}Cu{sub 3}O{sub 7}, where phonon structure observed in ceramic samples is absent in epitaxial oriented films and crystals because of the electronic screening due to the high conductivity of the a-b planes.
- Research Organization:
- Lawrence Berkeley Lab., CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States); Department of Defense, Washington, DC (United States); Center for Research in Superconductivity and Superconductivity Electronics (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 10161997
- Report Number(s):
- LBL-32148; CONF-9204169-1; ON: DE92017075
- Resource Relation:
- Conference: 2. symposium on high temperature superconductors in high frequency fields,Santa Fe, NM (United States),1-3 Apr 1992; Other Information: PBD: Mar 1992
- Country of Publication:
- United States
- Language:
- English
Similar Records
Submillimeter and microwave residual losses in epitaxial films of Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O
Submillimeter and microwave residual losses in epitaxial films of Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O