کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1677883 1009918 2011 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Atomic imaging using secondary electrons in a scanning transmission electron microscope: Experimental observations and possible mechanisms
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فناوری نانو (نانو تکنولوژی)
پیش نمایش صفحه اول مقاله
Atomic imaging using secondary electrons in a scanning transmission electron microscope: Experimental observations and possible mechanisms
چکیده انگلیسی

We report detailed investigation of high-resolution imaging using secondary electrons (SE) with a sub-nanometer probe in an aberration-corrected transmission electron microscope, Hitachi HD2700C. This instrument also allows us to acquire the corresponding annular dark-field (ADF) images both simultaneously and separately. We demonstrate that atomic SE imaging is achievable for a wide range of elements, from uranium to carbon. Using the ADF images as a reference, we studied the SE image intensity and contrast as functions of applied bias, atomic number, crystal tilt, and thickness to shed light on the origin of the unexpected ultrahigh resolution in SE imaging. We have also demonstrated that the SE signal is sensitive to the terminating species at a crystal surface. A possible mechanism for atomic-scale SE imaging is proposed. The ability to image both the surface and bulk of a sample at atomic-scale is unprecedented, and can have important applications in the field of electron microscopy and materials characterization.

Research highlights
► Atomic imaging using secondary electrons in an aberration-corrected electron microscope.
► High-resolution secondary electron imaging mechanism.
► Image contrast quantification and as functions of imaging conditions.
► Simultaneous acquisition of atomic images from surface and bulk.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ultramicroscopy - Volume 111, Issue 7, June 2011, Pages 865–876
نویسندگان
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