Superconductivity in Nb<sub>2</sub>Pd<sub>3</sub>Te<sub>5</sub> and Chemically-Doped Ta<sub>2</sub>Pd<sub>3</sub>Te<sub>5</sub>
Naoya Higashihara, Yoshihiko Okamoto, Yuma Yoshikawa, Youichi Yamakawa, Hiroshi Takatsu, Hiroshi Kageyama, Koshi Takenaka
Abstract
We report on the superconductivity in ternary transition metal tellurides Ta2Pd3Te5 and Nb2Pd3Te5, which have a one-dimensional crystal structure. Single-crystalline and polycrystalline samples of Ta2Pd3Te5 show nonmetallic electron conduction, while Ti or W doping results in metallic behavior with a bulk superconducting transition at 2-4 K. In contrast, the polycrystalline samples of Nb2Pd3Te5, which are found to be isostructural to Ta2Pd3Te5, show a bulk superconducting transition at 3.3 K. The crystal structure and physical properties of Ta2Pd3Te5 and Nb2Pd3Te5 are also discussed in comparison with a candidate excitonic insulator Ta2NiSe5.