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Title: Universal doping evolution of the superconducting gap anisotropy in single crystals of electron-doped Ba(Fe1–xRhx)2As2 from London penetration depth measurements

Journal Article · · Journal of Physics. Condensed Matter

Doping evolution of the superconducting gap anisotropy was studied in single crystals of 4d-electron doped Ba(Fe1–xRhx)2As2 using tunnel diode resonator measurements of the temperature variation of the London penetration depth Δλ(T). Single crystals with doping levels representative of an underdoped regime x = 0.039 (Tc = 15.5 K), close to optimal doping x = 0.057 (Tc = 24.4 K) and overdoped x = 0.079 (Tc = 21.5 K) and x = 0.131(Tc = 4.9 K) were studied. Superconducting energy gap anisotropy was characterized by the exponent, n, by fitting the data to the power-law, Δλ = ATn. The exponent n varies non-monotonically with x, increasing to a maximum n = 2.5 for x = 0.079 and rapidly decreasing towards overdoped compositions to 1.6 for x = 0.131. This behavior is qualitatively similar to the doping evolution of the superconducting gap anisotropy in other iron pnictides, including hole-doped (Ba,K)Fe2As2 and 3d-electron-doped Ba(Fe,Co)2As2 superconductors, finding a full gap near optimal doping and strong anisotropy toward the ends of the superconducting dome in the T-x phase diagram. The normalized superfluid density in an optimally Rh-doped sample is almost identical to the temperature-dependence in the optimally doped Ba(Fe,Co)2As2 samples. In conclusion, our study supports the universal superconducting gap variation with doping and pairing at least in iron based superconductors of the BaFe2As2 family.

Research Organization:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC02-07CH11358
OSTI ID:
1439427
Report Number(s):
IS-J-9665; TRN: US1900609
Journal Information:
Journal of Physics. Condensed Matter, Vol. 30, Issue 22; ISSN 0953-8984
Publisher:
IOP PublishingCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 2 works
Citation information provided by
Web of Science

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Figures / Tables (3)