Study of correlation between the electronic and crystal structures and the superconductivity in iron-based superconductors under pressure by x-ray diffraction and x-ray emission spectroscopy

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05194
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Yamaoka Hitoshi 国立研究開発法人理化学研究所, 放射光科学総合研究センター, 専任研究員 (30239850)
• Co-Investigator(Kenkyū-buntansha): 佐藤 仁 広島大学, 放射光科学研究センター, 准教授 (90243550) ; 水木 純一郎 関西学院大学, 理工学部, 教授 (90354977)
• Co-Investigator(Renkei-kenkyūsha): KAGAYAMA TOMOKO 大阪大学, 極限量子科学研究センター, 准教授 (40274675) ; TAKESHITA NAO 独立行政法人産業技術総合研究所, 電子光技術研究部門, 主任研究員 (60292760) ; SHIMADA KENYA 広島大学, 放射光科学研究センター, 教授 (10284225)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 高温超伝導 / 高圧 / X線発光分光 / X線回折

Outline of Final Research Achievements

Recently, in iron-based superconductors two superconducting (SC) domes, which are induced by pressure or doping, have been found and attracts many interests because of the origin of the two SC regions are possibly different. In this study we clarified the crystal and electronic structures of KxFe2-ySe, (NH3)yCs0.4FeSe, LnFeAsO1-xHx, which have two SC domes. The results show that tetragonal to collapsed tetragonal phase transition and electron correlation play key roles for the emergence of the SC2 and the superconductor type of SC2 may be different from that of SC1. In LaFeAsO1-xHx the superconductivity emerged in the region far from the tetrahedral crystal structure, while in SmFeAsO1-xHx it was observed near the tetrahedral crystal structure.

Free Research Field

数物系科学