Local corrugation and persistent charge density wave in ZrTe3 with Ni intercalation

TL;DR

This study investigates how Ni intercalation affects the electronic structure, charge density wave, and emergence of superconductivity in ZrTe3, revealing coexistence of CDW and superconductivity.

Contribution

It provides combined theoretical and experimental insights into the coexistence of CDW and superconductivity in Ni-intercalated ZrTe3, highlighting the role of intercalation.

Findings

Superconductivity appears at Ni doping levels where TCDW is reduced but persists.

Ni intercalates in the van-der-Waals gap, causing local lattice distortions.

CDW remains nearly unchanged in the presence of superconductivity.

Abstract

The mechanism of emergent bulk superconductivity in transition metal intercalated ZrTe3 is investigated by studying the effect of Ni doping on the band structure and charge density wave (CDW). The study reports theoretical and experimental results in the range of Ni0.01ZrTe3 to Ni0.05ZrTe3. In the highest doped samples bulk superconductivity with Tc < TCDW is observed, while TCDW is strongly reduced. Relativistic ab-initio calculations reveal Ni incorporation occurs preferentially through intercalation in the van-der-Waals gap. Analysis of the structural and elec- tronic effects of intercalation, indicate buckling of the Te-sheets adjacent to the Ni site akin to a locally stabilised CDW-like lattice distortion. Experiments by low temperature x-ray diffraction, angle-resolved-photoemission spectroscopy (ARPES) as well as temperature dependent resistivity reveal the nearly unchanged persistence of the CDW into the regime of bulk superconductivity. The CDW gap is found to be unchanged in its extent in momentum space, with the gap size also unchanged or possibly slightly reduced on Ni intercalation. Both experimental observations suggest that superconductivity coexists with the CDW in NixZrTe3.