FORMATION OF ARTIFICIAL BATIO3/SRTIO3 SUPERLATTICES USING PULSED-LASER DEPOSITION AND THEIR DIELECTRIC-PROPERTIES

We have formed strained dielectric superlattices of BaTiO3 (BTO) and SrTiO3 (STO) by a pulsed laser deposition technique. A large strain of 400-500 MPa is introduced at the interface between the BTO and STO layers. A large dielectric constant of 900 was observed with a stacking periodicity of 2 unit cells/2 unit cells. The superlattices show drastically different electrical behavior from that of the solid solution (Sr,Ba)TiO3 films. Broad maxima of the dielectric constants occur around 40-50-degrees-C and the values remain large even for a temperature above 200-degrees-C. (C) 1994 American Institute of Physics.