Evolution of superconductivity in K2−xFe4+ySe5: Spectroscopic studies of X-ray absorption and emission
學年 108
學期 1
出版（發表）日期 2019-11-05
作品名稱 Evolution of superconductivity in K2−xFe4+ySe5: Spectroscopic studies of X-ray absorption and emission
作品名稱（其他語言）
著者 H T Wang; Anirudha Ghosh; C H Wang; S H Hsieh; Y C Shao; J W Chiou; C L Chen; C W Pao; J F Lee; Y S Liu; Y D Chuang; J H Guo; M K Wu; W F Pong
單位
出版者
著錄名稱、卷期、頁數 Proceedings of the National Academy of Sciences of the United States of America, Volume 116, Issue 45 , p.22458-22463
摘要 This study investigates the evolution of superconductivity in K2-xFe4+ySe5 using temperature-dependent X-ray absorption and resonant inelastic X-ray scattering techniques. Magnetization measurements show that polycrystalline superconducting (SC) K1.9Fe4.2Se5 has a critical temperature (T c) of ∼31 K with a varying superconducting volume fraction, which strongly depends on its synthesis temperature. An increase in Fe-structural/vacancy disorder in SC samples with more Fe atoms occupying vacant 4d sites is found to be closely related to the decrease in the spin magnetic moment of Fe. Moreover, the nearest-neighbor Fe-Se bond length in SC samples exceeds that in the non-SC (NS) sample, K2Fe4Se5, which indicates a weaker hybridization between the Fe 3d and Se 4p states in SC samples. These results clearly demonstrate the correlations among the local electronic and atomic structures and the magnetic properties of K2-xFe4+ySe5 superconductors, providing deeper insight into the electron pairing mechanisms of superconductivity.
關鍵字 Fe vacancy disorder;X-ray absorption spectroscopy;resonant inelastic X-ray scattering;superconductivity
語言 en_US
ISSN 1091-6490
期刊性質 國外
收錄於 SCI
產學合作
通訊作者
審稿制度 否
國別 USA
公開徵稿
出版型式 ,電子版
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機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/118907 )