2009/11/30 by Nicholas P. Butch, N. P. Butch, S. R. Saha +8
Business, Management and Accounting · Materials Science · Physics and Astronomy · #Corporate Taxation and Avoidance #Intellectual Capital and Performance Analysis #Iron-based superconductors research #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.81.024518
published as Physical Review B 81, 024518 (2010) · 9 pgs, 10 figs, slightly revised, updated references
openalex publication_date 2010/01/27 · arxiv created 2010/01/29 · arxiv updated 2010/02/08 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Measurements of the Hall effect, thermoelectric power, magnetic susceptibility, and upper and lower critical fields were performed on single crystals of SrFe_2\ensuremath-xNixAs2, an FeAs-based superconducting system that exhibits a reduced superconducting transition temperature Tc in comparison to most other iron-pnictide superconductors. Studies of the Hall and thermoelectric responses indicate that Ni substitution in this system results in a dominant electronlike response, consistent with electron doping in other similar systems but with a weaker change in the Hall coefficient and a more gradual change in the thermoelectric response with Ni concentration. For optimally doped samples with full superconducting volume fraction, the lower and upper critical fields were determined to be Hc1(1.8 K)=0.08 T and Hc2(0)=25 T, respectively, with lower-Tc samples showing reduced values and indications of inhomogeneous superconductivity. Comparable to other higher-Tc FeAs-based materials, the temperature dependence of the upper critical field, \ensuremath∂Hc2/\ensuremath∂T, is linear over a wide temperature range, and the large values of Hc2(0) greatly exceed conventional estimates of paramagnetic and orbital limits.