Experimental Observation Of Pressure-Induced Superconductivity In Layered Transition-Metal Chalcogenides (Zr,Hf)Gete4 Explored By A Data-Driven Approach

Layered transition metal chalcogenides (Zr,Hf)-GeTe4 were screened from the AtomWork database as potential pressure-induced superconductors by having a narrow bandgap and high density of states near the Fermi level. Single-crystal samples of (Zr,Hf)GeTe4 were then synthesized, and their compositional ratio, crystal structures, and valence states were investigated via energy-dispersive X-ray spectroscopy, single-crystal X-ray diffraction, and X-ray photoelectron spectroscopy, respectively. The pressure-induced superconductivity in both crystals was first time reported by using a diamond anvil cell with a boron-doped diamond electrode and an undoped diamond insulating layer. The maximum superconducting transition temperatures of ZrGeTe4 and HfGeTe4 were 6.5 K under 57 GPa and 6.6 K under 60 GPa, respectively. The structural phase transition under high pressure was discussed by using Raman investigation.