Microwave surface resistance of YBa sub 2 Cu sub 3 O sub 7 thin films on LaAIO sub 3 substrates

Journal Article · Sat Sep 01 04:00:00 EDT 1990 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.346493· OSTI ID:6429978

Cooke, D W; Gray, E R; Arendt, P N; Elliott, N E; Rollett, A D; Schofield, T G ^[1]; Mogro-Campero, A; Turner, L G ^[2]

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1. Los Alamos National Laboratory, Los Alamos, NM (USA)
2. GE Research and Development Center, Schenectady, NY (USA)

The surface resistance {ital R}{sub {ital s}} of YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) thin films (0.6{plus minus}0.1 {mu}m) deposited onto 2.5-cm diam (100) LaAlO{sub 3} substrates has been measured at 22 GHz using both Cu and Nb cavities. The surface resistance falls precipitously at the superconducting transition ({Tc} =90 K) from a normal state value of approximately 2 {Omega} to a 77 K value of 13.7{plus minus}1 m{Omega}, which is 1.6 times lower than Cu. At 4 K the surface resistance is 1{plus minus}0.1 m{Omega}, as measured in a Nb superconducting cavity, which is an order of magnitude lower than Cu. The critical current density at 77 K is 4.5{times}10{sup 4} A/cm{sup 2}. Pole figure analyses show the ratio of {ital c}-axis to {ital a}-axis-oriented material in the film is 2.4:1. YBCO films deposited onto either LaGaO{sub 3} or LaAlO{sub 3} substrates with varying {ital c}/{ital a} ratios yield surface resistance values at 77 K that are crudely correlated with {ital R}{sub {ital s}}. Therefore, the principal effect of orienting the material is to improve the sharpness of the high-frequency superconducting transition, consistent with the notion that the sharpness is associated with {ital intergranular} rather than {ital intragranular} properties.

• OSTI ID: 6429978
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 68:5; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRITICAL CURRENT
CURRENTS
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
ELECTROMAGNETIC RADIATION
FILMS
FREQUENCY RANGE
GHZ RANGE
GHZ RANGE 01-100
HIGH-TC SUPERCONDUCTORS
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
LOW TEMPERATURE
MICROWAVE RADIATION
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RADIATIONS
RARE EARTH COMPOUNDS
SUBSTRATES
SUPERCONDUCTORS
SURFACES
TRANSITION ELEMENT COMPOUNDS
ULTRALOW TEMPERATURE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES