TY - JOUR
T1 - Electron microscopy study of preferential variant selection in copt alloy ordered under a magnetic field
AU - Akamine, Hiroshi
AU - Farjami, Sahar
AU - Mitsuhara, Masatoshi
AU - Nishida, Minoru
AU - Fukuda, Takashi
AU - Kakeshita, Tomoyuki
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013
Y1 - 2013
N2 - Transmission electron microscope (TEM) and scanning transmission electron microscope (STEM) observations were carried out to investigate microstructure formation and variant selection process in L10-type ordered CoPt alloy upon a two-step ordering heat-treatment. The first step corresponds to nucleation process carried out under a magnetic field of 10 T and the second step represents growth process without magnetic field. After the first step of ordering, ordered domains of about 5 nm in size were observed and fraction of the preferred variant with the c-axis parallel to applied magnetic field was slightly higher than that of the other two variants. Formation of tweed microstructure along {011}L10 was confirmed at the initial stage of ordering. This structure is considered to be derived from the periodic alignment of interface between two ordered variants with twin relation. At the early stage of the second step of ordering, numerous micro-twins were formed through tweed microstructure and the volume fraction of the preferred variant was increased accompanying with modulation of twins, while that of other two variants was decreased. After the second step of ordering, the twins were vanished and single variant was obtained.
AB - Transmission electron microscope (TEM) and scanning transmission electron microscope (STEM) observations were carried out to investigate microstructure formation and variant selection process in L10-type ordered CoPt alloy upon a two-step ordering heat-treatment. The first step corresponds to nucleation process carried out under a magnetic field of 10 T and the second step represents growth process without magnetic field. After the first step of ordering, ordered domains of about 5 nm in size were observed and fraction of the preferred variant with the c-axis parallel to applied magnetic field was slightly higher than that of the other two variants. Formation of tweed microstructure along {011}L10 was confirmed at the initial stage of ordering. This structure is considered to be derived from the periodic alignment of interface between two ordered variants with twin relation. At the early stage of the second step of ordering, numerous micro-twins were formed through tweed microstructure and the volume fraction of the preferred variant was increased accompanying with modulation of twins, while that of other two variants was decreased. After the second step of ordering, the twins were vanished and single variant was obtained.
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U2 - 10.2320/matertrans.MAW201313
DO - 10.2320/matertrans.MAW201313
M3 - Article
AN - SCOPUS:84883257251
VL - 54
SP - 1715
EP - 1718
JO - Materials Transactions
JF - Materials Transactions
SN - 0916-1821
IS - 9
ER -