Superlattice formation of (Ba,Sr)TiO3 prepared by metal-organic chemical vapor deposition

Abstract

Dielectric superlattices of (Ba0.5Sr0.5)TiO3 (BST) grown by a metal-organic chemical vapor deposition (MOCVD) have been studied by transmission electron microscopy (TEM). A selected area of electron diffraction patterns clearly show satellite spots that indicate the formation of superlattice of BST film. A superlattice distance is 6.75 Angstrom, that is, 2.4 times of (110) BST plans distance. A high-resolution TEM study revealed that the superlattices were induced by the periodic composition modulation of Ba and Sr atoms. A possible atomic arrangement model of the superlattice was proposed by a simulation with a national center for electron microscopy simulation system (NCEMSS). (C) 2001 Elsevier Science B.V. All rights reserved.