Abstract
Break junction tunneling spectroscopy measurements have been carried out on the novel layered nitride superconductor ZrNCl 1- x (\(x\cong 0.3\)) with T c =12–14 K. Two kinds of gap structures are reproducibly observed, both of which can be described by the BCS density of states. Values of the gap parameters at 4 K are obtained to be Δ=1.6–2.3 meV and 4.0–5.1 meV. Upon warming, these gap structures disappear at T c , thereby giving the ratio 2Δ/ k B T c =2.7–3.8 and 6.6–8.4, respectively. The former is within the value of conventional superconductors, while the latter is extremely large in comparison with that of the conventional strong-coupling superconductors. The larger ratio is similar to the value of high- T c cuprates. The origins of such two kinds of gaps are discussed.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
