Thickness-dependent dielectric and electrocaloric properties of Pb0.85La0.1(Zr0.85Ti0.15)O3 antiferroelectric thin thins on stainless steel substrates

Pb0.85La0.1(Zr0.85Ti0.15)O-3 (PLZT) antiferroelectric (AFE) thin films with different thicknesses were prepared by the sol-gel method on LaNiO3 (LNO)-buffered stainless steel (SS) substrates. X-Ray diffraction (XRD) analysis and scanning electron microscopy (SEM) pictures indicate that all samples were of pure perovskite structure with a smooth and flat surface. The intensity of (110) diffraction peaks increases with increasing the PLZT thickness, indicating the (110) preferred orientation. The maximum polarization (P-max) and dielectric constant (epsilon(r)) of PLZT thin films increase dramatically and the dielectric loss decreases with increasing the film thickness. PLZT thin films exhibit the good insulation properties with the leakage current density of about 10(-8) A/cm(2) orders of magnitude. Moreover, the temperature and entropy change are of Delta T = 17.0 degrees C and Delta S = 56.0 J . K-1 . kg(-1) for PLZT thin films with thickness of 960 nm at AE = 600 kV/cm, revealing a large electrocaloric effect at room temperature. Our results showed that PLZT thin films deposited on flexible stainless steel substrates would be great interests for solid-cooling equipments.

Automated summary

PLZT antiferroelectric thin films with different thicknesses were prepared on LaNiO3-buffered stainless steel substrates by the sol-gel method. XRD analysis and SEM pictures confirmed the pure perovskite structure and smooth surface of the films. The results showed that increasing film thickness led to higher polarization, dielectric constant, and reduced dielectric loss. Additionally, the PLZT thin films exhibited good insulation properties and a large electrocaloric effect at room temperature.