Abstract:
A new method has been established to compute the
variants of point
defect clusters depending on their symmetry. Results are presented! for close-
packed clusters of up to five point defects in cubic crystals. Interesting) relations
among the variants of point defect clusters in two and three dimensiqnal lattice
structures have been noted. Computer simulation techniques haye
been
employed to determine the relaxed structures and energies of sortie planar
defects using manv-body potentials developed by Ackland et at. (198ir).
The structures of some low index twin boundaries, e g. (130), (1j23), (140)
and
(114)
in
Copper,
are
explored
4?
to examine their
energy
configurations. In (140) and (114) twin boundaries local atomic adjustments
are made to obtain low interfacial energy. The atomic planes
twin interface in all the cases. The interactions of
coalesce at the
vacancy with (1$0), (123),
(140) and (114) boundaries are studied. For single vacancy the maximum
binding energy for (123) and (114) boundary is observed when
vacancy lies at
the plane adjacen: to the interface.
The structures and energies of (111), (001) and (110) twist boundaries
with
different
misorientation
angles
in copper, silver, and
investigated as well. It is observed that in-plane translations are
flold
necessary to
establish low energy (110) twist boundary.
