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Comment on “Diffraction Method Detection of Local Lattice Distortion in AlN Ceramics by Convergent Beam Electron”
Author(s) -
Callahan Daniel L.
Publication year - 1996
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1996.tb08025.x
Subject(s) - electron diffraction , materials science , yttrium , diffraction , lattice (music) , crystal structure , condensed matter physics , crystallography , optics , chemistry , physics , metallurgy , oxide , acoustics
H aving read with interest the paper by Nakahata et al. on the use of convergent beam electron diffraction (CBED) to examine lattice distortions in AlN, 1 this author writes to elucidate several subtleties in the application of quantitative CBED analysis which may influence the conclusions drawn from the published report. In Nakahata et al. 's work, two primary structural observations were made, that the AlN crystal near the yttrium aluminate grainboundary phase was distorted and that the lattice near the AlN/AlN grain boundary was not distorted. Energy dispersive X‐ray spectroscopy (EDS) could discern no compositional variation in the AlN. These observations were used to support the proposition that the observed lattice distortion is caused mainly by the thermal expansion mismatch between AlN and the grainboundary phase. However, close examination of the data presented indicates that solutionized oxygen may be the primary cause of the distortion.