کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8038167 1518327 2015 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Efficient phase contrast imaging in STEM using a pixelated detector. Part II: Optimisation of imaging conditions
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فناوری نانو (نانو تکنولوژی)
پیش نمایش صفحه اول مقاله
Efficient phase contrast imaging in STEM using a pixelated detector. Part II: Optimisation of imaging conditions
چکیده انگلیسی
In Part I of this series of two papers, we demonstrated the formation of a high efficiency phase-contrast image at atomic resolution using a pixelated detector in the scanning transmission electron microscope (STEM) with ptychography. In this paper we explore the technique more quantitatively using theory and simulations. Compared to other STEM phase contrast modes including annular bright field (ABF) and differential phase contrast (DPC), we show that the ptychographic phase reconstruction method using pixelated detectors offers the highest contrast transfer efficiency and superior low dose performance. Applying the ptychographic reconstruction method to DPC segmented detectors also improves the detector contrast transfer and results in less noisy images than DPC images formed using difference signals. We also find that using a minimum array of 16×16 pixels is sufficient to provide the highest signal-to-noise ratio (SNR) for imaging beam sensitive weak phase objects. Finally, the convergence angle can be adjusted to enhance the contrast transfer based on the spatial frequencies of the specimen under study.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ultramicroscopy - Volume 151, April 2015, Pages 232-239
نویسندگان
, , ,