Study of the microstructures and the strain of PbZr0.53Ti0.47O3/La1.85Sr0.15CuO4 integrated films

A series of PbZr0.53Ti0.47O3 (PZT)/La1.85Sr0.15CuO4 (LSCO) integrated films were grown on SrTiO3 (STO)(001) substrates by DC/RF magnetron sputtering m ethod. The film thickness of the PZT changes from 500 to 9000 Angstrom, whi le that of the LSCO is kept at 1000 Angstrom. The microstructures of interf ace and surface of the bilayer film have been investigated by small-angle X -ray reflection, high-resolution X-ray diffraction (XRD) using synchrotron radiation, scanning electron microscopy (SEM) and transmission electron mic roscopy (TEM). The SEM images show island-like growth of the PZT layers wit h the particle size changing from 0.1 to 0.4 mu m, while the thickness of t he PZT layer increased from 500 to 9000 Angstrom. The Full width at half ma ximums (FWHMs) of diffraction peak of the PZT layers are dramatically large r than that of LSCO layers, and the internal strains of the PZT layers are larger than that of LSCO films by an order. This indicated that the crystal perfection of the LSCO layers are better compared with PZT layers, and we attribute this to the different growth molds for PZT and LSCO films. Howeve r, no grand strain transition layers were found either in the PZT/LSCO or i n the LSCO/PZT interfaces. (C) 2000 Elsevier Science B.V. All rights reserv ed.