Physics – Condensed Matter – Superconductivity
Scientific paper
2008-12-12
New J. Phys. 11, 035006 (2009)
Physics
Condensed Matter
Superconductivity
20 pages, 11 figures
Scientific paper
10.1088/1367-2630/11/3/035006
The presence of macroscopic phase separation into superconducting and magnetic phases in LaFeAsO$_{1-x}$F$_x$ (LFAOF) and CaFe$_{1-x}$Co$_x$AsF (CFCAF) is demonstrated by muon spin rotation (muSR) measurement across their phase boundaries ($x=0.06$ for LFAOF and $x=0.075$--0.15 for CFCAF). In LFAOF, both magnetism and superconductivity develop simultaneously below a common critical temperature, $T_m =~ T_c =~ 18$ K, where the magnetism is characterized by strong randomness. A similar, but more distinct segregation of these two phases is observed in CFCAF, where the magnetic phase retains $T_m$ as close to that of the parent compound ($T_c << T_m =~ 80$--120 K) and the superconducting volume fraction is proportional to the Co content $x$. The close relationship between magnetism and superconductivity is discussed based on these experimental observations. Concerning superconducting phase, an assessment is made on the anisotropy of order parameter in the superconducting state of LFAOF, CFCAF, and Ba$_{1-x}$K$_x$Fe$_2$As$_2$ (BKFA, $x=0.4$) based on the temperature dependence of superfluid density [$n_s(T)$] measured by muSR. The gap parameter, $2\Delta/k_BT_c$, determined from $n_s(T)$ exhibits a tendency that hole-doped pnictides (BKFA) is much greater than those in electron-doped ones (LFAOF, CFCAF), suggesting difference in the coupling to bosons mediating the Cooper pairs between relevant $d$ electron bands.
Kadono Ryosuke
Takeshita Shu
No associations
LandOfFree
Competition/Coexisitence of Magnetism and Superconductivity in Iron Pnictides Probed by Muon Spin Rotation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Competition/Coexisitence of Magnetism and Superconductivity in Iron Pnictides Probed by Muon Spin Rotation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Competition/Coexisitence of Magnetism and Superconductivity in Iron Pnictides Probed by Muon Spin Rotation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-609926