Visualizing chemical states and defects induced magnetism of graphene oxide by spatially-resolved-X-ray microscopy and spectroscopy
學年 104
學期 1
出版(發表)日期 2015-10-20
作品名稱 Visualizing chemical states and defects induced magnetism of graphene oxide by spatially-resolved-X-ray microscopy and spectroscopy
作品名稱(其他語言)
著者 Wang, Y.F.; Singh, S.B.; Limaye, M.V.; Shao, Y.C.; Hsieh, S.H.; Chen, L.Y.; Hsueh, H.C.; Wang, H.T.; Chiou, J.W.; Yeh, Y.C.; Chen, C.W.; Chen, C.H.; Ray, S.C.; Wang, J.; Pong, W.F.; Takagi, Y.; Ohigashi, T.; Yokoyama, T.; Kosugi, N.
單位
出版者
著錄名稱、卷期、頁數 Scientific Reports 5, pp.15439-15451
摘要 This investigation studies the various magnetic behaviors of graphene oxide (GO) and reduced graphene oxides (rGOs) and elucidates the relationship between the chemical states that involve defects therein and their magnetic behaviors in GO sheets. Magnetic hysteresis loop reveals that the GO is ferromagnetic whereas photo-thermal moderately reduced graphene oxide (M-rGO) and heavily reduced graphene oxide (H-rGO) gradually become paramagnetic behavior at room temperature. Scanning transmission X-ray microscopy and corresponding X-ray absorption near-edge structure spectroscopy were utilized to investigate thoroughly the variation of the C 2p(π*) states that are bound with oxygen-containing and hydroxyl groups, as well as the C 2p(σ*)-derived states in flat and wrinkle regions to clarify the relationship between the spatially-resolved chemical states and the magnetism of GO, M-rGO and H-rGO. The results of X-ray magnetic circular dichroism further support the finding that C 2p(σ*)-derived states are the main origin of the magnetism of GO. Based on experimental results and first-principles calculations, the variation in magnetic behavior from GO to M-rGO and to H-rGO is interpreted, and the origin of ferromagnetism is identified as the C 2p(σ*)-derived states that involve defects/vacancies rather than the C 2p(π*) states that are bound with oxygen-containing and hydroxyl groups on GO sheets.
關鍵字
語言 en
ISSN 2045-2322
期刊性質 國外
收錄於 SCI
產學合作 國內 國外
通訊作者
審稿制度
國別 GBR
公開徵稿
出版型式 ,電子版,紙本
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機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/107093 )