Environmental stability and anisotropic resistivity of Co-doped Na1-delta Fe1-xCoxAs

TitleEnvironmental stability and anisotropic resistivity of Co-doped Na1-delta Fe1-xCoxAs
Publication TypeJournal Article
Year of Publication2012
AuthorsSpyrison N, Tanatar MA, Cho K, Song Y, Dai PC, Zhang CL, Prozorov R
Journal TitlePhysical Review B
Date Published10
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberWOS:000310130000002
Keywordshigh-temperature superconductivity, iron

Temperature-dependent resistivity is studied in single crystals of iron-arsenide superconductor Na1-delta Fe1-xCoxAs for electrical current directions along, rho(a)(T), and transverse, rho(c)(T), to the Fe-As layers. Doping with Co increases stability of this compound to reaction with the environment and suppresses numerous features in both rho(a)(T) and rho(c)(T) compared to the stoichiometric NaFeAs. Evolution of rho(a)(T) with x follows a universal trend observed in other pnictide superconductors, exhibiting a T-linear temperature dependence close to the optimal doping and development of T-2 dependence upon further doping. rho(c)(T) in parent compound shows a nonmonotonic behavior with a crossover from nonmetallic resistivity increase on cooling from room temperature down to similar to 80 K to a metallic decrease below this temperature. Both rho(a)(T) and rho(c)(T) show several correlated crossoverlike features at T > 80 K. Despite a general trend towards more metallic behavior of interplane resistivity in Co-doped samples, the temperature of the crossover from insulating to metallic behavior (80 K) does not change much with doping.

URL<Go to ISI>://WOS:000310130000002
Alternate JournalPhys. Rev. B