The effect of three-fold astigmatism on measurements of grain boundary volume expansion by high-resolution transmission electron microscopy.

Journal Article · Wed Apr 01 04:00:00 EST 1998 · J. Microsc.

DOI:https://doi.org/10.1046/j.1365-2818.1998.2890841.x· OSTI ID:938043

Merkle, K L; Csencsits, R; Rynes, K L; Withrow, J P; Stadelmann, P A; MXIC, Batiment

In the absence of high-order aberrations, the lattice fringe technique should allow measurement of grain boundary rigid-body displacements to accuracies about an order of magnitude better than the point-to-point resolution of the transmission electron microscope. The three-fold astigmatism, however, introduces shifts of the lattice fringe pattern that depend on the orientation of the lattice relative to the direction of the three-fold astigmatism and thus produces an apparent shift between the two grains bordering the grain boundary. By image simulation of grain boundary model structures, the present paper explores the effect of these extraneous shifts on grain boundary volume expansion measurements. It is found that the shifts depend, among others, on zone axis direction and the magnitude of the lattice parameter. For many grain boundaries of interest, three-fold astigmatism correction to better than 100 nm appears necessary to achieve the desired accuracies.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: ER
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 938043
• Report Number(s): ANL/MSD/JA-26116
• Journal Information: J. Microsc., Journal Name: J. Microsc. Journal Issue: Pts. 1/2 ; Apr/May 1998 Vol. 190; ISSN JMICAR; ISSN 0022-2720
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ACCURACY
CHROMATIC ABERRATIONS
GRAIN BOUNDARIES
LATTICE PARAMETERS
ORIENTATION
RESOLUTION
TRANSMISSION ELECTRON MICROSCOPY