[Lecture]Advanced transmission electron ...
Advanced transmission electron microscopy and its applications in material sciences
Jianqi Li, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P. R. China.
Date: March 12, 2010 (Friday)
Time: 10:00am
Location: MSE Building 210 conference room
Abstract: Recent progresses in the fields of high-resolution electron microscopy (Cs-TEM), electron energy loss spectroscopy and electron holography have been briefly reviewed. It is emphasized that numerous significant structural issues in material science could be well addressed. For instance, charge ordering and oxygen deficiency in functional oxides, magnetic tunnel junctions with MgO-barrier and the manganite-based heterojunctions. My talk will also focus on some experimental results on interfacial structural features and oxygen diffusion in SrTiO3/Si films and related heterojunctions. High-resolution TEM investigations on the La0.9Sr0.1MnO3/SrTiO3/Si heterojunctions suggested that the thickness of the SiOx interfacial layer change visibly from one sample to another grown under slightly different conditions. The electron-energy loss spectroscopy analyses on the LSMO/STO/Si interfacial region indicated that the Si ions are in intermediate oxidation states in the amorphous layer. Electron holography measurements revealed that notable negative charges accumulate in the amorphous SiOx layer, the energy barrier between the Si substrate and the LSMO film have been estimated based on experimental data.
References:
1. C. Ma, H. X. Yang, H. F. Tian, H. L Shi, J. B. Lu, Z. W. Wang, L. J. Zeng, G. F. Chen, N. L. Wang, and J. Q. Li*, Physical Review B (R) ) 79 (2009) 060506.
2. H.Y Liang , H.X. Xu, J. Q.Li, J. Am. Chem. Soc. 131(2009)6068.
3. L. J. Zeng, C. Ma, H. X. Yang, R. J. Xiao, and J. Q. Li*, Physical Review B 77 (2008) 024107.
4. Y. Zhang, H. X. Yang , C. Ma, H. F. Tian & J. Q. Li *, Phys. Rev. Lett. 98 (2007) 247602.
5. Z. A. Li, H. X. Yang, H. F. Tian, J. Q. Li*, J. R. Cheng, J. G. Chen, Appl. Phys. Lett. 90 (2007)182904
