Position averaged convergent beam electron diffraction: Theory and applications

James LeBeau, Scott Findlay, Leslie Allen, Susanne Stemmer

Research output: Contribution to journalArticleResearchpeer-review

140 Citations (Scopus)

Abstract

A finely focused angstrom-sized coherent electron probe produces a convergent beam electron diffraction pattern composed of overlapping orders of diffracted disks that sensitively depends on the probe position within the unit cell. By incoherently averaging these convergent beam electron diffraction patterns over many probe positions, a pattern develops that ceases to depend on lens aberrations and effective source size, but remains highly sensitive to specimen thickness, tilt, and polarity. Through a combination of experiment and simulation for a wide variety of materials, we demonstrate that these position averaged convergent beam electron diffraction patterns can be used to determine sample thicknesses (to better than 10 ), specimen tilts (to better than 1 mrad) and sample polarity for the same electron optical conditions and sample thicknesses as used in atomic resolution scanning transmission electron microscopy imaging.
Original languageEnglish
Pages (from-to)118 - 125
Number of pages8
JournalUltramicroscopy
Volume110
Issue number2
DOIs
Publication statusPublished - 2010
Externally publishedYes

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