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-In-person
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).
–
Presenters
-
Makariy Tanatar
- Ames National Laboratory