Volume 101, Number 1, January 2013
|Number of page(s)||5|
|Section||Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties|
|Published online||18 January 2013|
Evidence for nodeless superconducting gap in NaFe1−xCoxAs from low-temperature thermal conductivity measurements
1 State Key Laboratory of Surface Physics, Department of Physics, and Laboratory of Advanced Materials, Fudan University - Shanghai 200433, PRC
2 Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China - Hefei, Anhui 230026, PRC
Received: 2 December 2012
Accepted: 20 December 2012
The thermal conductivity of optimally doped NaFe0.972Co0.028As (Tc ∼ 20 K) and overdoped NaFe0.925Co0.075As (Tc ∼ 11 K) single crystals were measured down to 50 mK. No residual linear term κ0/T is found in zero magnetic field for both compounds. Applying a field H = 3 T (≈Hc2/12) does not noticeably increase κ0/T in NaFe1.972Co0.028As. The κ0/T of overdoped NaFe1.925Co0.075As shows a field dependence similar to the optimally doped BaFe1.85Co0.15As2. All these results suggest nodeless superconducting gaps in NaFe1−xCoxAs from the optimal doping to the overdoped regime, with low anisotropy or ratio between the magnitudes of different gaps.
PACS: 74.70.Xa – Pnictides and chalcogenides / 74.25.fc – Electric and thermal conductivity
© EPLA, 2013
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.