Characteristics of (La1−xSrx)MnO3 and (La1−xSrx)CoO3 buffer materials and their effect on ferroelectric properties of (Pb1−xSrx)TiO3 thin films

Abstract

The performance of new buffer materials, (La0.5Sr0.5)MnO3 (LSMO) deposited on uncoated or Pt-coated silicon substrates by pulsed laser deposition process was systematically investigated and was compared with those of (La0.5Sr0.5)CoO3 (LSCO) materials. Perovskite LSMO and LSCO thin films can be obtained by depositing the materials at 500–700°C substrate temperature (in 0.02–10.00 mbar oxygen pressure), regardless of substrate materials. LSMO/Pt (or LSCO/Pt) double layer electrode materials possess pronouncedly smaller electrical resistivity than those of LSMO (or LSCO) single layer electrode materials and, thereafter, are more suitable for applying as buffer layers for the synthesis of (Pb0.6Sr0.4)TiO3 (PSrT) thin films. PSrT/LSMO/Pt(Si) thin films have ferroelectric properties as good as LSCO-buffered PSrT thin films. They own dielectric constant k≅3000, remanent polarization Pr =18 − 20 μC/cm2 and coercive field Ec =44.6 − 51.4 kV/cm. However, LSMO electrode materials perform more satisfactorily due to better handling endurance of PSrT/LSMO/Pt(Si) thin films during post-processing for device fabrication.