ENHANCED ELECTROCALORIC PROPERTIES OF PMN-PT THIN FILMS WITH LSCO BUFFER LAYERS

Lead magnesium niobate-lead titanate (PMN-PT) ferroelectric thin films were deposited on Ir/SrTiO3/TiN/Si (001) substrates by oxygen plasma assisted pulsed laser deposition (PLD) method. Effects of the lanthanum strontium cobaltite (LSCO) buffer layer between the PMN-PT film and the Ir layer on the crystallinity, microstructure, ferroelectric properties and electrocaloric effect of the film were investigated. Results show that the LSCO buffer layer can improve the crystallinity and electrocaloric properties effectively. By applying a voltage of 5V to the PMN-PT thin film without the LSCO buffer layer, the changes in the reversible adiabatic temperature measured at room temperature and at 508 K are respectively 0.73 K and 2.13 K, while by introducing a LSCO buffer layer, the corresponding values are increased to 1.41 K and 4.25 K.