2002/10/17 by C. Panagopoulos, J. L. Tallon, B. D. Rainford +6 · 4 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Iron-based superconductors research #Physics of Superconductivity and Magnetism #cond-mat.supr-con
paper · pdf · doi:10.1016/s0038-1098(02)00667-1
published as Solid State Communications Vol. 126, 47 (2003) · Invited Paper: Post-muSR2002 Superconductivity Workshop
arxiv created 2002/10/17 · openalex publication_date 2003/03/26 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the spin fluctuations of pure and Zn-substituted high temperature superconductors (HTS) using the muon spin relaxation (muSR) technique. Superconductivity is found to coexist with low frequency spin fluctuations over a large region of the superconducting phase diagram. The characteristic temperature of spin fluctuations detected by muSR decreases with increasing doping and vanishes above a critical doping pc=0.19 where the normal state pseudogap vanishes. Furthermore, it is at pc that our penetration depth studies show an abrupt change in the doping dependence of the superfluid density. For p>pc the absolute value of the superfluid density is large and nearly independent of carrier concentration whereas for p<pc it drops rapidly, signalling a crossover to weak superconductivity. These results are discussed in terms of a quantum transition involving fluctuating short-range magnetic order that separates the superconducting phase diagram of HTS into two distinct ground states.