2009/05/16 by S. J. Singh, Shiv J. Singh, Jai Prakash +8
Chemistry · Materials Science · Physics and Astronomy · #Analytical Chemistry (journal) #Charge carrier #Chemistry #Cobalt #Condensed matter physics #Doping #Electrical resistivity and conductivity #Electron #Electronic correlation #FOS: Physical sciences #Hall effect #Iron-based superconductors research #Magnetic and transport properties of perovskites and related materials #Magnetic field #Magnetoresistance #Materials science #Penetration depth #Physics #Rare-earth and actinide compounds #Seebeck coefficient #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity #Superconductivity (cond-mat.supr-con) #Weak localization #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.0905.2679
published in arXiv (Cornell University) (Cornell University)
arxiv created 2009/05/16 · openalex publication_date 2009/05/16 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Electron-doping of the semimetal (CeOFeAs) by either fluorine (max Tc ~ 43 K)or cobalt (max Tc ~ 11 K) leads to superconductivity. Here we show the effect of transition metal (Co) substitution at the iron site on the superconducting properties of CeO0.9F0.1FeAs (Tc ~38 K)to understand the interplay of charge carriers in both the rare earth-oxygen and Fe-As layers. Simultaneous doping of equivalent number of charge carriers in both layers leads to a Tc of 9.8 K which is lower than the Tc obtained when either the conducting layer (CeAs) or charge reservoir layer (CeO) is individually doped. This suggests a clear interplay between the two layers to control the superconductivity. The resistivity shows a T2 dependence (T >>Tc) which indicates strong electron-electron correlation. Hall coefficient and thermoelectric power indicate increased carrier concentration with cobalt doping in CeO0.9F0.1FeAs. The rf penetration depth both for CeO0.9F0.1Fe0.95Co0.05As and CeO0.9F0.1FeAs show an exponential temperature dependence with a gap value of ~ 1.6 and 1.9 meV. A resistance minimum is observed in the normal state near Tc which also shows negative magnetoresistance and provides evidence for the onset of weak localization.