Superconductivity and Kondo effect driven by cobalt intercalation in Zirconium ditelluride (ZrTe2)

Abstract

We carried out an investigation of the electrical properties of the Co-intercalated ZrTe2 compound Co0.08ZrTe2. This compound exhibits metallic behavior at ambient temperature with the electrical resistivity (ρ) dropping linearly upon cooling from 300 to 60 K. The electrical resistivity shows a minimum near Tmin≈18 K upon further cooling, and the low temperature upturn is interrupted by the onset of superconductivity at Tc≈3.8 K, with the zero-resistivity state being reached at T≈2.0 K. The minimum in electrical resistivity is consistent with the Kondo scattering and the behavior of ρ(T) near Tmin is analyzed in the context of the Hamman model, yielding excellent fits considering the presence of Co2+ ions in octahedral sites within the van der Waals gaps of ZrTe2. Electrical resistivity measurements under pressures up to 23.6 kbar show the suppression of the superconductivity and an increase in the Kondo temperature TK at intermediate pressures, with strong reduction at higher pressures. This behavior is accompanied by a suppression of Ruderman-Kittel-Kasuya-Yosida correlations at intermediate pressures, followed by a resurgence at higher pressures, reflecting the oscillatory nature of the exchange coupling energy with respect to the distance between impurity ions.

Source-reported materials — not catalogue approval

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