Detailed Study Of Structural And Ferroelectric Properties In Batio3/La2/3ca1/3mno3 Bilayers Deposited By Pulsed Laser Deposition

We have deposited ferroelectric BaTiO3 (BTO), and ferromagnetic La2/3Ca1/3MnO3 bilayers on SrTiO3 substrates by pulsed laser deposition at pure oxygen atmosphere and substrate temperature of 820 degrees C, keeping fixed the magnetic layer thickness (tLCMO) at 50 nm and varying the thickness of the ferroelectric layer (tBTO) from 20 to 100 nm. X-ray diffraction analysis indicates a textured growth of both layers. The lattice parameter of the La2/3Ca1/3MnO3 layer is slightly modified by the presence of the BaTiO3 layer. Resistivity versus temperature Arrhenius plots show a small polaron thermally activated conductivity in bilayers with activation energies from 120 to 135 meV. Polarization loops at the BaTiO3 measured at room temperature, using the La2/3Ca1/3MnO3 layer as bottom electrode, show a maximum remnant polarization of 20 degrees C/cm(2) and minimal coercive field of 70 kV/cm. Thus, the bilayers maintain marked ferroelectric and ferromagnetic properties on individual layers.