Submillimeter and microwave residual losses in epitaxial films of Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O

Journal Article · Sat Aug 01 00:00:00 EDT 1992 · Journal of Superconductivity; (United States)

DOI:https://doi.org/10.1007/BF00618138· OSTI ID:7233479

Miller, D; Richards, P L ^[1]; Garrison, S M; Newman, N ^[2]; Eom, C B; Geballe, T H ^[3]; Etemad, S; Inam, A; Venkatesan, T ^[4]; Martens, J S ^[5]

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1. Univ. of California, Berkeley, CA (United States) Lawrence Berkeley Lab., CA (United States)
2. Conductus, Inc., Sunnyvale, CA (United States)
3. Stanford Univ., CA (United States)
4. Bell Communications Research, Red Bank, NJ (United States)
5. Sandia National Lab., Albuquerque, NM (United States); and others

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-T[sub c] 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. 44 refs., 6 figs., 3 tabs.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 7233479
• Journal Information: Journal of Superconductivity; (United States), Journal Name: Journal of Superconductivity; (United States) Vol. 5:4; ISSN 0896-1107; ISSN JOUSEH
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
665411 -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AC LOSSES
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BOLOMETERS
CALCIUM COMPOUNDS
CERAMICS
COPPER COMPOUNDS
CORRELATIONS
CUPRATES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
ELECTRONIC STRUCTURE
ELECTRONS
ELEMENTARY PARTICLES
ENERGY LOSSES
EPITAXY
EQUIPMENT
FERMIONS
FILMS
FREQUENCY DEPENDENCE
HIGH-TC SUPERCONDUCTORS
KRAMERS-KRONIG CORRELATION
LEPTONS
LOSSES
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
MICROWAVE RADIATION
NUCLEAR MODELS
OXYGEN COMPOUNDS
PHONONS
PHYSICAL PROPERTIES
QUASI PARTICLES
RADIATIONS
RESONATORS
SCREENING
SUPERCONDUCTIVITY
SUPERCONDUCTORS
THALLIUM COMPOUNDS
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
WEAK-COUPLING MODEL
YTTRIUM COMPOUNDS