Campus Units
Physics and Astronomy, Ames Laboratory
Document Type
Article
Publication Version
Published Version
Publication Date
10-1-2010
Journal or Book Title
Physical Review B
Volume
82
Issue
13
First Page
134528
DOI
10.1103/PhysRevB.82.134528
Abstract
Temperature-dependent interplane resistivity, rho(c)(T), was used to characterize the normal state of the iron-arsenide superconductor Ba(Fe1-xCox)(2)As-2 over a broad doping range 0 <= x <= 0.50. The data were compared with in-plane resistivity, rho(a)(T), and magnetic susceptibility, chi(T), taken in H perpendicular to c, as well as Co NMR Knight shift, K-59, and spin-relaxation rate, 1/T1T. The interplane resistivity data show a clear correlation with the NMR Knight shift, assigned to the formation of the pseudogap. Evolution of rho(c)(T) with doping reveals two characteristic energy scales. The temperature of the crossover from nonmetallic, increasing on cooling, behavior of rho(c)(T) at high temperatures to metallic behavior at low temperatures, T*, correlates well with an anomaly in all three magnetic measurements. This characteristic temperature, equal to approximately 200 K in the parent compound, x = 0, decreases with doping and vanishes near x* approximate to 0.25. For doping levels x >= 0.166, an additional feature appears above T* with metallic behavior of rho(c)(T) found above the low-temperature resistivity increase. The characteristic temperature of this charge-gap formation, T-CG, vanishes at x(CG) similar or equal to 0.30, paving the way to metallic, T linear, rho(c)(T) close to x(CG) and superlinear T dependence for x > x(CG). None of these features are evident in the in-plane resistivity rho(c)(T). For doping levels x < x(CG), chi(T) shows a known, anomalous, T-linear dependence, which disappears for x > x(CG). These features are consistent with the existence of a charge gap, accompanying formation of the magnetic pseudogap, and its critical suppression with doping. The inferred c-axis charge gap reflects the three-dimensional character of the electronic structure and of the magnetism in the iron arsenides.
Copyright Owner
American Physical Society
Copyright Date
2010
Language
en
File Format
application/pdf
Recommended Citation
Tanatar, Makariy A.; Ni, Ni; Thaler, Alexander N.; Bud’ko, Sergey L.; Canfield, Paul C.; and Prozorov, Ruslan, "Pseudogap and its critical point in the heavily doped Ba(Fe1-xCox)(2)As-2 from c-axis resistivity measurements" (2010). Physics and Astronomy Publications. 690.
https://lib.dr.iastate.edu/physastro_pubs/690
Comments
This article is published as Tanatar, M. A., Ni Ni, A. Thaler, S. L. Bud’ko, P. C. Canfield, and R. Prozorov. "Pseudogap and its critical point in the heavily doped Ba (Fe 1− x Co x) 2 As 2 from c-axis resistivity measurements." Physical Review B 82, no. 13 (2010): 134528. DOI: 10.1103/PhysRevB.82.134528. Posted with permission.