Topic
Contrast transfer function
About: Contrast transfer function is a research topic. Over the lifetime, 934 publications have been published within this topic receiving 26533 citations.
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TL;DR: In this paper, a wave optical treatment of surface step contrast in a low-energy electron microscopy (LEEM) imaging system is presented, where the aberrations of an idealised LEEM imaging system are directly incorporated into a transfer function (TF) and image simulations of surface steps are evaluated in one and two dimensions.
Abstract: A wave optical treatment of surface step contrast in a low-energy electron microscopy (LEEM) is presented. The aberrations of an idealised LEEM imaging system are directly incorporated into a transfer function (TF) and image simulations of surface steps are evaluated in one and two dimensions. Under the special circumstances of a weak phase object, the simplified form of the contrast transfer function (CTF) is used to discuss LEEM image contrast and optimum defocus conditions.
20 citations
TL;DR: In this paper, the origin of multiple solution in maximum entropy image deconvolution has been analyzed for simple crystal structures and the entropy-defocus curves contain two kinds of peaks, sharp peaks originate in the loss of at least one diffracted beam due to the defined threshold for contrast transfer function.
20 citations
TL;DR: In this article, the refractive-index distribution parameters of a gradient-index rod lens were determined to most fit the observed data, by carrying out the computer simulation for ray tracing with the approximate solution of ray equation.
Abstract: Spherical aberration was measured and, by carrying out the computer simulation for ray tracing with the approximate solution of ray equation, the refractive-index distribution parameters of a gradient-index rod lens were determined to most fit the observed data.
20 citations
TL;DR: In this article, the sub-Angstrom probe of an aberration-corrected scanning transmission electron microscope was used to enable imaging and analysis of nanostructures and interfaces with unprecedented resolution and sensitivity.
Abstract: The sub-Angstrom probe of an aberration-corrected scanning transmission electron microscope will enable imaging and analysis of nanostructures and interfaces with unprecedented resolution and sensitivity. In conjunction with first-principles theory, new insights are anticipated into the atomistic processes of growth and the subtle link between structure and functionality. We present initial results from the aberration-corrected microscopes at Oak Ridge National Laboratory that indicate the kinds of studies that will become feasible in the near future. Examples include (1) the three-dimensional location and identification of individual dopant and impurity atoms in semiconductor interfaces, and their effect on local electronic structure; (2) the accurate reconstruction of surface atomic and electronic structure on nanocrystals, and the effect on optical properties; and (3) the ability to distinguish which configurations of catalyst atoms are active, and why.
20 citations
TL;DR: In this article, a spherical aberration correction of the objective lens has shown a new possibility for the observation of nanometre-sized tubular materials using high-resolution transmission electron microscopy (HRTEM).
20 citations