Doping evolution of the absolute value of the London penetration depth and superfluid density in single crystals of Ba(Fe_1-xCo_x)₂As₂

Journal Article · Fri Aug 06 00:00:00 EDT 2010 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PhysRevB.82.054507· OSTI ID:1065260

Gordon, R. T. ^[1]; Kim, H. ^[1]; Salovich, N. ^[2]; Giannetta, R. W. ^[2]; Fernandes, R. M. ^[1]; Kogan, V. G. ^[3]; Prozorov, T. ^[3]; Bud’ko, S. L. ^[1]; Tanatar, M. A. ^[3]; Prozorov, R. ^[1]; Canfield, P. C. ^[1]

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1. Ames Lab., Ames, IA (United States); Iowa State Univ., Ames, IA (United States)
2. Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States)
3. Ames Lab., Ames, IA (United States)

The zero-temperature value of the in-plane London penetration depth, λ_ab (0) , has been measured in single crystals of Ba(Fe_1-x Co_x)₂ As₂ as a function of the Co concentration, x , across both the underdoped and overdoped superconducting regions of the phase diagram. For x ≳ 0.047 , λ_ab (0) has been found to have values between 120 ± 50 and 300 ± 50 nm . A pronounced increase in λ_ab (0) , to a value as high as 950 ± 50 nm , has been observed for x ≲ 0.047 , corresponding to the region of the phase diagram where the itinerant antiferromagnetic and superconducting phases coexist and compete. Direct determination of the doping-dependent λ_ab (0) has allowed us to track the evolution of the temperature-dependent superfluid density, from which we infer the development of a pronounced superconducting gap anisotropy at the edges of the superconducting dome.

• Research Organization: Energy Frontier Research Centers (EFRC) (United States). Center for Emergent Superconductivity (CES)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1065260
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 82, Issue 5; Related Information: CES partners with Brookhaven National Laboratory (BNL); Argonne National Laboratory; University of Illinois, Urbana-Champaign; Los Alamos National Laboratory; ISSN 1098-0121: PRBMDO
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
phonons
thermal conductivity
energy storage (including batteries and capacitors)
superconductivity
defects
spin dynamics