Interplane Resistivity of Underdoped Single Crystals (Ba₁₋ₓKₓ)Fe₂As₂ (0 ≤ x < 0.34)
The temperature-dependent interplane resistivity ρc(T) was measured in the hole-doped iron arsenide superconductor (Ba1-xKx)Fe2As2 over a doping range from parent compound to optimal doping at Tc ≈ 38 K, 0 ≤ x ≤ 0.34. The measurements were undertaken on high-quality single crystals grown from FeAs flux. The coupled magnetic/structural transition at TSM leads to a clear accelerated decrease of ρc(T) on cooling in samples with Tc < 26 K (x < 0.25). This decrease in the hole-doped material is in notable contrast to the increase in ρc(T) in the electron-doped Ba(Fe1-xCox)Fe2As2 and isoelectron-substituted BaFe2(As1-xPx)2. TSM decreases very sharply with doping, dropping from Ts = 71 K to zero on increase of Tc from approximately 25 to 27 K. ρc(T) becomes linear in T close to optimal doping. The broad crossover maximum in ρc(T), found in the parent BaFe2As2 at around Tmax ∼ 200 K, shifts to higher temperature ∼250 K with doping of x = 0.34. The maximum shows clear correlation with the broad crossover feature found in the temperature-dependent in-plane resistivity ρa(T). The evolution with doping of Tmax in (Ba1-xKx)Fe2As2 is in notable contrast with both the rapid suppression of Tmax found in Ba(Fe1-xTx)2As2 (T = Co,Rh,Ni,Pd) and its rapid increase in BaFe2(As1-xPx)2. This observation suggests that pseudogap features are much stronger in hole-doped than in electron-doped iron-based superconductors, revealing significant electron-hole doping asymmetry similar to that in the cuprates.
M. A. Tanatar and W. E. Straszheim and H. Kim and J. Murphy and N. Spyrison and E. C. Blomberg and K. Cho and J. P. Reid and B. Shen and For full list of authors, see publisher's website., "Interplane Resistivity of Underdoped Single Crystals (Ba₁₋ₓKₓ)Fe₂As₂ (0 ≤ x < 0.34)," Physical Review B - Condensed Matter and Materials Physics, vol. 89, no. 14, article no. 144514, American Physical Society (APS), Apr 2014.
The definitive version is available at https://doi.org/10.1103/PhysRevB.89.144514
International Standard Serial Number (ISSN)
Article - Journal
© 2014 American Physical Society (APS), All rights reserved.
30 Apr 2014
U.S. Department of Energy, Grant None