Search for Pressure-Induced Superconductivity in Chalcogen Hydrides

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K14659
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: Osaka University
• Principal Investigator: EINAGA Mari 大阪大学, 基礎工学研究科, 助教 (70709899)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 圧力誘起超伝導 / 水素化合物 / 高温高圧合成 / 放射光粉末X線回折

Outline of Final Research Achievements

In this study, for the aim of finding new high-temperature superconductors, we have synthesized hydride of selenium, which is one of chalcogen as well as sulfur, and searched for its superconductivity. Selenium hydride was synthesized under high temperature and high pressure by injection infrared laser into selenium and hydrogen loaded in diamond anvil cell, and then, pressurized up to 150 GPa at low temperature to prevent pressure-induced molecular dissociation near room temperature. At this pressure, temperature dependence of electrical resistance shows sharp drops in resistance at around 30 K and 20 K. Although the crystal structure of the synthesized sample is not decided, the decrease in resistance might be caused superconducting transition of selenium hydride, which can correspond to the low-Tc phase of sulfur hydride obtained by low temperature compression.

Free Research Field

高圧科学

Academic Significance and Societal Importance of the Research Achievements

近年の水素化合物における高温超伝導の発見により、金属水素や水素化合物における室温超伝導体への期待や興味が社会的・学術的にも高まっている。多くの理論グループにより硫化水素や他の水素化物の圧力誘起超伝導の予測が行われているものの、超高圧下実験の特殊さ、特に電子輸送特性測定の難しさから実験的な超伝導観測に関する報告は、世界においても少ない。その中でも本研究成果は、硫黄と同族のセレンの水素化物の研究によって、この系の超伝導機構の体系的な理解を進めるものである。