Data-driven Exploration of Pressure-Induced Superconductivity in AgIn5Se8
Abstract
Candidates compounds for new thermoelectric and superconducting materials, which have narrow band gap and flat bands near band edges, were exhaustively searched by a high-throughput first-principles calculation from an inorganic materials database named AtomWork. We focused on AgIn5Se8 which has high density of state near the Fermi level. AgIn5Se8 was successfully synthesized as single crystals using a melt and slow cooling method. The single-crystal X-ray diffraction analysis revealed the obtained crystal is high quality without deficiencies. The valence states in AgIn5Se8 were determined to be Ag1+, In3+ and Se2- in accordance with a formal charge by the core level X-ray photoelectron spectroscopy analysis. The electrical resistance was evaluated under high pressure using a diamond anvil cell with boron-doped diamond electrodes. Although the sample was insulator with a resistance of above 40 M at ambient pressure, the resistance markedly decreased with increase of the pressure, and a pressure-induced superconducting transition was discovered at 3.4 K under 52.5 GPa. The transition temperature increased up to 3.7 K under further pressure of 74.0 GPa.