• Title/Summary/Keyword: Exit-plane wave function

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Simulated Images of the Second Derivative of the Exit-plane Wavefunction Giving Sub-50 pm Resolutions in HRTEM (HRTEM에서 50 pm 이하 분해를 주는 결정 밑 표면 파동함수의 2차 도함수의 시뮬레이션 영상들)

  • Kim, Hwang-Su
    • Applied Microscopy
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    • v.39 no.2
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    • pp.175-183
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    • 2009
  • In this paper we present sub-50 pm resolution images of atom columns simulated with the negative of the second derivative of the exit-plane wave function (EPW). The EPW can be retrieved from a focal series reconstruction in the (high resolution) transmission electron microscopy (HRTEM). The simulated images are for Si and InAs in [114] and [116] orientations, which give about sub-50 pm separations of atom columns. The theoretical reason for the validity of this method is given from analysis based on the kinematical diffraction theory, and the limitation for applicability of this method also is discussed.

A Review of IWFR Method for HRTEM Image Analysis and Application (HRTEM영상 분석에 대한 IWFR 방법의 고찰 및 응용)

  • Kim, Hwang-Su
    • Applied Microscopy
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    • v.38 no.1
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    • pp.63-72
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    • 2008
  • The iterative wave-function reconstruction (IWFR) method developed by Allen et al. (2004) was reviewed with concern for its applicability. The high resolution transmission electron microscopy (HRTEM) studies of the materials such as GaAs, $YBa_2Cu_3O_7$ and $Al_2CuMg$ reported in the literature were utilized in this review. In this process the basis of validity, the limiting conditions and the information limit of this method were discussed. It was particularly noted that the phase contrast image of the exit plane wave evaluated from this method reveals not only $C_s$-corrected atomic resolution within information limit, but also strong tendency of contrast proportional to the magnitude of the atomic number of compositional atoms in a crystal.