Ubiquitous Matthiessen rule violation in hole-doped iron-based superconductor Ba<sub>1-x</sub>K<sub>x</sub>Fe<sub>2</sub>As<sub>2</sub> with controlled disorder
ORAL
Abstract
Systematic evolution of the temperature dependent electrical resistivity with doping is one of the hallmarks of magnetically mediated mechanism of superconductivity [1].
While in electron doped and iso-electron-substituted BaFe2As2 resistivity turns into T-linear at optimum doping, it shows a pronounced non-linear feature in the hole-doped
Ba1-xKxFe2As2.
Here we report the evolution of the temperature-dependent electrical resistivity, ρ(T), of Ba1-xKxFe2As2 with artificial disorder induced by low temperature electron irradiation. Measurements were made for the composition range 0.22≤ x ≤ 1. We find ubiquitous violation of the Matthiessen rule, correlating with a crossover feature in ρ(T) at T* ∽200~K. The increased sensitivity to disorder at low temperatures is consistent with dominant contribution of low-density high mobility carriers, as suggested by anomalously large and temperature-dependent Hall effect in these compounds. Possible origins of this scenario will be discussed.
[1] N.D. Mathur et al. Nature (London) 394, 39 (1998).
While in electron doped and iso-electron-substituted BaFe2As2 resistivity turns into T-linear at optimum doping, it shows a pronounced non-linear feature in the hole-doped
Ba1-xKxFe2As2.
Here we report the evolution of the temperature-dependent electrical resistivity, ρ(T), of Ba1-xKxFe2As2 with artificial disorder induced by low temperature electron irradiation. Measurements were made for the composition range 0.22≤ x ≤ 1. We find ubiquitous violation of the Matthiessen rule, correlating with a crossover feature in ρ(T) at T* ∽200~K. The increased sensitivity to disorder at low temperatures is consistent with dominant contribution of low-density high mobility carriers, as suggested by anomalously large and temperature-dependent Hall effect in these compounds. Possible origins of this scenario will be discussed.
[1] N.D. Mathur et al. Nature (London) 394, 39 (1998).
*This work was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences, Materials Science and Engineering Division. The research was performed at the Ames Laboratory, which is operated for the U.S. DOE by Iowa State University under contract DE-AC02-07CH11358. Electron irradiation was conducted at the “SIRIUS” accelerator facility at École Polytechnique (Palaiseau, France) and was supported by EMIR\&A French network (FR CNRS 3618) proposals 17-3646 and 18-5155.
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Presenters
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Makariy A. Tanatar
- Ames National Laboratory