FERROELECTRIC DOMAINS IN EPITAXIAL PBTIO3 AND BATIO3 THIN-FILMS ON MGO(100)

Epitaxial PbTiO3 and BaTiO3 thin films were pl spared on MgO(100) by l aser ablation and RF magnetron sputter deposition, respectively. X-ray diffraction (XRD), transmission electron microscopy (TEM), and atomic force microscopy (AFM) were used to investigate the ferroelectric dom ains in the grown films. in the PbTiO3 film, significant portions of a -domains were distributed in c-domains, which causes abundant 90 degre es domain population, On the other hand, the BaTiO3 film was mainly si ngle c-domains without any meaningful domain structure. We attribute t he difference in domain population of the two films to two reasons. On e is the smaller phase transformation strain which comes from smaller tetragonality of BaTiO3, and the other is the larger compressive stres s due to thermal mismatch which comes from lower T-c, of BaTiO3 than t hose of PbTiO3. (C) 1998 Elsevier Science S.A.