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Cover Image, Volume 97, Issue 5
Publication year - 2014
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Reports
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.12993
Subject(s) - birefringence , crystallite , materials science , micrograph , spinel , mineralogy , shrinkage , composite material , impurity , optics , scanning electron microscope , metallurgy , chemistry , physics , organic chemistry
Crack that formed during hot‐pressing of a transparent polycrystalline magnesium aluminate (MgAl 2 O 4 ) spinel compact. Color change is from birefringence caused by uniaxial strain due to lattice shrinkage caused by MgO vaporization. Dark spots at upper left are spherical clusters of abnormal grains originating from an unknown impurity (10X objective, polarized light, first‐order retardation plate). Micrograph courtesy Marc Rubat du Merac.