Non-conventional superconducting fluctuations in Ba(Fe1-xRhx)(2)As-2 iron-based superconductors
We measured the static uniform spin susceptibility of Ba(Fe1−xRhx)2As2 iron-based superconductors, over a broad range of doping (0.041 ≤ x ≤ 0.094) and magnetic fields. At small fields (H ≤ 1 kOe) we observed, above the transition temperature Tc, the occurrence of precursor diamagnetism, which is not ascribable to the Ginzburg–Landau theory. On the contrary, our data agree with a phase fluctuation model, which has been used to interpret a similar phenomenology occurring in the high-Tc cuprate superconductors. Additionally, in the presence of strong fields, the unconventional fluctuating diamagnetism is suppressed, whereas Ginzburg–Landau fluctuations are found, in agreement with literature.
This is a peer-reviewed, un-copyedited version of an article accepted for publication/published in Journal of Physics: Condensed Matter. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at DOI: 10.1088/0953-8984/26/40/405703. Posted with permission.