DIELECTRIC-PROPERTIES OF BATIO3 SRTIO3 MULTILAYERED THIN-FILMS PREPARED BY PULSED-LASER DEPOSITION/

BaTiO3/SrTiO3 multilayered thin films were deposited on Si and Pt/Si s ubstrates. X-ray diffraction clearly shows the formation of the supers tructures. Phase transition properties were studied via dielectric mea surements. Glassy behavior, characterized by a strong frequency disper sion of dielectric properties, was found in samples with a total thick ness of 400 nm, while in samples with a total thickness of 800 nm, nor mal ferroelectric phase transitions with two dielectric peaks were obs erved. A preliminary interpretation assumes that size effects which fr ustrate long range ferroelectric ordering may lead to the relaxational behavior in BaTiO3/SrTiO3 superstructures. (C) 1998 American Institut e of Physics.