Influence of fluorination on electronic states and electron transport properties of Sr2IrO4 thin films
Influence of fluorination on electronic states and electron transport properties of Sr2IrO4 thin films
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DOI：
10.1039/d0tc01734e
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发表时间：
2020-06
影响因子：
6.4
通讯作者：
T. Maruyama;A. Chikamatsu;T. Katayama;K. Kuramochi;H. Ogino;M. Kitamura;K. Horiba;H. Kumigashira;T. Hasegawa
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文献类型：
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作者：
T. Maruyama;A. Chikamatsu;T. Katayama;K. Kuramochi;H. Ogino;M. Kitamura;K. Horiba;H. Kumigashira;T. Hasegawa
我们采用脉冲激光沉积与拓扑共晶相结合的方法制备了层状钙钛矿结构的Sr 2 IrO 4 − xF 2x薄膜，并研究了其结构、电子态和电子输运性质。SrO岩盐层中的氟离子嵌入和部分氧离子的脱除同时发生，而Ir ~（4+）保留。氟的量被评估为2 × 103，这比体积值大得多。光学和光电子能谱测量表明，由于氟的电负性很大，有效总角动量Jeff = 3/2在电子轰击后是稳定的。Sr 2 IrO 4 − xF 2x薄膜表现出半导体行为，用Efros-Shklovskii变程跳跃描述，ρ（T）<$T−1/2。这些结果将有助于通过阴离子掺杂来改变电子态，以探索Ruddlesden-Popper型铱酸盐前所未有的物理性质。
We fabricated layered-perovskite Sr2IrO4−xF2x thin films by combining pulsed-laser deposition with topotactic fluorination and investigated their structures, electronic states, and electron transport properties. In the fluorination process, the insertion of fluorine into SrO rock-salt layers and the partial removal of oxygen occurred simultaneously while keeping Ir4+. The fluorine amount was evaluated to be 2x ≈ 3, which was much larger than the bulk value. Optical and photoemission measurements revealed that the effective total angular momentum Jeff = 3/2 is stabilized upon fluorination owing to the large electronegativity of fluorine. The Sr2IrO4−xF2x film exhibited a semiconducting behavior described by Efros–Shklovskii variable-range hopping with ρ(T) ≈ T−1/2. These results will be useful for modifying electronic states by anion doping to explore unprecedented physical properties in Ruddlesden–Popper-type iridates.