Completely (001)-textured growth and electrical properties of Bi4Ti3O12/LaNiO3 heterostructures prepared by pulsed laser deposition on LaAlO3 single crystal substrates

Heterostructures of Bi4Ti3O12(BTO)/LaNiO3(LNO) have been prepared on (001) LaAlO3 single crystal substrates by pulsed laser deposition (PLD). Analyses of X-ray diffraction (XRD), (including theta-2theta scan, rocking curve), atomic force microscopy (AFM) and scanning electron microscopy (SEM) reveal that the high quality LNO and BTO films are completely c-axis oriented. With Pt top electrodes, the BTO films exhibit a highly insulative characteristic of low leakage current (similar to10(-7) A /cm(2) at an applied voltage of 6 V) and excellent dielectric properties. At 100 kHz, the dielectric constant and dielectric loss are 238 and 0.033, respectively. Also a well symmetric ferroelectric hysteresis loop is observed with remnant polarization P-r of 4.5 muC/cm(2) and coercive field E-c of 72.5 kV/cm. Our experiments confirm that the use of the LNO as an electrode material can reduce the amount of the interfacial charges, and thus remove the imprint failure due to thermal processes. (C) 2002 Elsevier Science B.V. All rights reserved.