Nodal Gap in Fe-Based Layered Superconductor LaO 0.9 F 0.1-δ FeAs Probed by Specific Heat Measurements
2008; Institute of Physics; Volume: 25; Issue: 6 Linguagem: Inglês
10.1088/0256-307x/25/6/082
ISSN1741-3540
AutoresGang Mu, Xiyu Zhu, Fang Lei, Lei Shan, Cong Ren, Wen Hai‐Hu,
Tópico(s)Magnetic and transport properties of perovskites and related materials
ResumoWe report the specific heat measurements on the newly discovered Fe-based layered LaO0.9F0.1-δFeAs superconductor with the onset transition temperature Tc ≈ 28K. A nonlinear magnetic field dependence of the electronic specific heat coefficient γ(H) has been found in the low temperature limit, which is consistent with the prediction for a nodal superconductor. The maximum gap value Δ0 ≈ 3.4 ± 0.5 meV is derived by analysing γ(H) based on the d-wave model. We also detected the electronic specific heat difference between 9 T and 0 T in a wide temperature range, a specific heat anomaly can be clearly observed near Tc. The Debye temperature of our sample is determined to be about 315.7K. Our results suggest an unconventional mechanism for this new superconductor.
Referência(s)