Publications by authors named "Ko-Feng Chen"

An electrostatic phase plate can provide better phase contrast, a fact that plays a promising role for the high-resolution observation of specimens containing light elements. However, in order to quantify the "phase" contrast from images recorded using the phase plate, the "absorption" (or scattering) contrast arising from electrons scattered elastically and inelastically outside of the phase-plate ring must be analyzed. Angular distributions of the elastic and inelastic scattering are predicted using the Lenz model.

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This paper demonstrates the applicability of electron-spectroscopic imaging (ESI) for valence-state mapping of the iron oxide system. We have previously developed a set of signal-processing methods for an ESI series, to allow mapping of sp(2)/sp(3) ratio, dielectric function and energy bandgap. In this study, these methods are applied to generate a valence-state map of an iron oxide thin film (Fe/alpha-Fe(2)O(3)).

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