Resonant photoemission and X-ray absorption spectroscopies of lithiated magnetite thin film
Resonant photoemission and X-ray absorption spectroscopies of lithiated magnetite thin film
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DOI：
10.7567/jjap.56.04ck01
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发表时间：
2017-01
影响因子：
1.5
通讯作者：
T. Tsuchiya;K. Kawamura;W. Namiki;Shoto Furuichi;M. Takayanagi;M. Minohara;Masaki Kobayashi;K. Horiba;H. Kumigashira;K. Terabe;T. Higuchi
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文献类型：
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作者：
T. Tsuchiya;K. Kawamura;W. Namiki;Shoto Furuichi;M. Takayanagi;M. Minohara;Masaki Kobayashi;K. Horiba;H. Kumigashira;K. Terabe;T. Higuchi
利用共振光电子能谱（RPES）和X射线吸收光谱（XAS）研究了锂化对Fe 3 O 4薄膜电子结构的影响，并与纳米离子器件的工作机制相关，从而实现磁性调谐。通过对锂化Fe_3O_4（Li-Fe_3 O_4）与纯Fe_3O_4的Fe 2 p XAS谱的比较，发现锂化增加了八面体B位Fe ~（2+）离子的数量。Li-Fe_3 O_4的价带RPES谱进一步表明，锂化增加了费米能级附近的态密度，导致八面体B位上的Fe ~（2+）离子。这些发现与观察到的Li-Fe 3 O 4薄膜的磁化-磁场（M-H）环中的饱和磁化强度的降低很好地一致，表明少数自旋（下自旋）增加（即，总自旋减少）。在B站点的Fe 2+离子的数量的变化被建议是基于纳米离子的磁性调谐装置的基本操作机制。
Resonant photoemission spectroscopy (RPES) and X-ray absorption spectroscopy (XAS) were used to investigate the effect of lithiation on the electronic structure of Fe3O4 thin film relevant to the operation mechanism of nanoionic devices to enable magnetic property tuning. Comparison of the Fe 2p XAS spectrum for lithiated Fe3O4 (Li–Fe3O4) with that for pristine Fe3O4 clearly demonstrated that the number of Fe2+ ions at octahedral B sites is increased by lithiation. The valence band RPES spectra of Li–Fe3O4 further showed that lithiation increases the density of states near the Fermi level originating Fe2+ ions at octahedral B sites. These findings agree well with the observed decrease in the saturation magnetization in the magnetization–magnetic field (M–H) loop of Li–Fe3O4 thin film, indicating that minority spins (down spins) increase (i.e., total spins decrease) due to lithiation. The variation in the number of Fe2+ ions at B sites is suggested to be an underlying operating mechanism of a nanoionics-based magnetic property tuning device.