Measurement of the superconducting energy gap in La-Ba-Cu oxide and La-Sr-Cu oxide

Journal Article · Tue Mar 31 23:00:00 EST 1987 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.35.5330· OSTI ID:6046883

Sulewski, P E; Sievers, A J; Russek, S E; Hallen, H D; Lathrop, D K; Buhrman, R A

We report on far-infrared (FIR) reflectivity measurements on sintered pressed powder samples of La-Ba-Cu oxide and La-Sr-Cu oxide. The best samples show fairly sharp transitions to zero measurable resistance with a transition midpoint of 28 K for the Ba alloy and 36 K for the Sr alloy. The FIR measurements reveal an energy gap below T/sub c/ with, depending on the measurement criterion used, values of 2..delta../k/sub B/T/sub c/ of 1.3--1.95 for La-Ba-Cu oxide and 1.6--2.7 for La-Sr-Cu oxide, which are lower than expected for a BCS superconductor.

• Research Organization: Laboratory of Atomic and Solid State Physics and Materials Science Center, Cornell University, Ithaca, New York 14853-2501
• OSTI ID: 6046883
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 35:10; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
DATA
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROMAGNETIC RADIATION
ENERGY GAP
EXPERIMENTAL DATA
FAR INFRARED RADIATION
INFORMATION
INFRARED RADIATION
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
NUMERICAL DATA
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POWDERS
RADIATIONS
RARE EARTH COMPOUNDS
REFLECTIVITY
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTIVITY
SURFACE PROPERTIES
TRANSITION ELEMENT COMPOUNDS