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layer deposited to avoid the diffusion of Ti across the interfaces into Pt layer and PZT films and forming Pt 3Ti and TiO 2 on the surface of Pt electrode [6,12] that cause aging and fatigue of the PZT ferroelectric capacitors. The total thickness of this conductive barrier is about 250 nm. The La1 .xSrxCoO 3 (LSCO) bottom electrodes with the composition x=0.25, 0.50 and 0.75 were deposited on the Pt-coated substrates at 700 0C by pulsed laser deposition using the KrF excimer laser ( LPX205i, Lambda Physik ) of 248 nm in wavelength, 30 ns in pulse width and 5 Hz in repetition rate. The laser energy is 140 mJ per shot. The thickness of the LSCO layer is about 30 nm. The PTZT ferroelectric films were also deposited at 700'C and the laser energy used was 190 mJ per shot. The PTZT films were in-situ annealed in the chamber with a 0.5 atmosphere pure oxygen pressure. The top LSCO electrodes were deposited at 600'C by pulsed laser deposition using a shadow mask with holes 0.2 mm in diameter. The laser energy was 140 mJ per shot. This substrate temperature will result in the metallic conductive behavior of the LSCO films [13]. The crystal structures of the heterostructures were studied by the X-ray 0-20 scan using CuKct radiation, and the surface morphology of the PTZT films and the cross-section morphology of the heterostructure were investigated by scanning electron microscopy (SEM)( JEOL JSM-6300). Rutherford backscattering spectrum study was also carried out for the heterostructure. The composition of the nominal LSCO films were investigated by inductively coupled plasma quantemeter (ICP) which shows stoichiometry except oxygen composition. In fact, we should use La1 .xSrxCoO3.8 instead of Laj.xSrCoO3 due to the oxygen vacancy in the LSCO film. Electric measurements for the ferroelectric capacitors were made using a pulsed testing system ( Radiant Technologies, RT6000HVS ). The P-V hysteresis loops were obtained with a bipolar voltage in a virtual ground mode. The leakage current was measured by using HP4140B, PA Meter/DC Voltage Source. RESULTS AND DISCUSSIONS Figure ](a) shows the X-ray 0-20 scan pattern using CuK• radiation from the films of PTZT deposited on Pt/TiO 2/Si0 2/Si(001) wafer. Although the bottom electrode Pt was oriented, the PTZT grains were oriented along -, - and -directions, respectively. The (110)-peak has the strongest intensity. No undesirable pyrochlore phase could be observed, and all of the PTZT films were crystallized with perovskite structure. Figure 1(b) shows the X-ray 0-20 scan pattern of Lal.-SrxCoO 3 films deposited on Pt/TiO 2/Si0 2/Si(001) substrates with Sr-concentration x=0.25, 0.50 and 0.75, respectively, which indicates that Lao.25Sr 0 .7SCoO 3 films are strongly -textured. The X-ray 0-20 scan pattern from the films of PTZT deposited on Pt/TiO 2 /Si0 2/Si(001) wafers using La 1 _xSrxCoO 3 buffer layers is shown in figure 1(c). It is obvious that the composition of La1 _xSrCoO 3 has large influence on the orientation of the PTZT grains. With the increase of Sr-concentration the PT