Meng Qingping, Xu Guangyong, Xin Huolin, Stach Eric A, Zhu Yimei, Su Dong
J Phys Chem A. 2019 May 30;123(21):4632-4637. doi: 10.1021/acs.jpca.9b02802. Epub 2019 May 16.
The interfacial electronic distribution in transition-metal oxide thin films is crucial to their interfacial physical or chemical behaviors. Core-loss electron energy-loss spectroscopy (EELS) may potentially give valuable information of local electronic density of state at high spatial resolution. Here, we studied the electronic properties at the interface of Pb(ZrTi)O (PZT)/4.8 nm LaSrMnO (LSMO)/SrTiO (STO) using valance-EELS with a scanning transmission electron microscope. Modeled with dielectric function theory, the charge transfer in the vicinity of the interfaces of PZT/LSMO and LSMO/STO was determined from the shifts of plasma peaks of valence EELS (VEELS), agreeing with theoretical prediction. Our work demonstrates that the VEELS method enables a high-efficient quantification of the charge transfer at interfaces, shedding light on the charge-transfer issues at heterogenous interfaces in physical and chemical devices.
过渡金属氧化物薄膜中的界面电子分布对其界面物理或化学行为至关重要。芯损失电子能量损失谱（EELS）有可能在高空间分辨率下提供有关局部电子态密度的有价值信息。在此，我们使用扫描透射电子显微镜的价电子能量损失谱研究了Pb(ZrTi)O（PZT）/4.8纳米LaSrMnO（LSMO）/SrTiO（STO）界面处的电子特性。根据介电函数理论建模，通过价电子能量损失谱（VEELS）等离子体峰的位移确定了PZT/LSMO和LSMO/STO界面附近的电荷转移，这与理论预测相符。我们的工作表明，VEELS方法能够高效地量化界面处的电荷转移，为物理和化学器件中异质界面的电荷转移问题提供了线索。
