Analysis of misfit relaxation in heteroepitaxial BaTiO3thin films

Abstract

Abstract The misfit relaxation mechanism of BaTiO3 thin films of different thicknesses grown two-dimensionally on SrTiO3(100) substrates by pulsed laser deposition was analysed using X-ray diffraction and transmission electron microscopy. Major defects in partially relaxed films are misfit dislocations with Burgers vectors of type a(100), threading dislocations connected to those dislocations, and inclined threading dislocations with Burgers vectors of type a(110). Misfit and threading dislocations with equivalent Burgers vectors of type a(100) constitute half-loops. a(110) threading dislocations are formed by the kinetic reaction between these half-loops. In addition, two types of dislocation dissociation in a(100) misfit dislocations and a(110) threading dislocations are found by high-resolution observation. The dissociation of this misfit dislocation takes place with increasing film thickness and generates stacking faults with displacement vectors of type 1/2a(101). Misfit relaxation depends on the hal...