Abstract
Atomic structures of [001] symmetric tilt grain boundaries (GBs) in barium titanate were analyzed using atomistic simulation technique. It is found that atomic configuration of GB is optimally relaxed with accompanying the rigid body translations of grains to minimize the deficiency in the coordination numbers of Ti4+ ions and to suppress the structural distortion at the GBs. The resultant excess energy of GB depends on the number density of the coordination-deficient Ti4+ ions, indicating that maintenance and formation of Ti4+-O2- bonds at GB are closely related to structural modification and stabilization of GB.
