Fabrication of the transparent ferroelectric heterostructures based on KNN-based lead-free films

Abstract

Transparent and epitaxial 0.95(K0.49Na0.49Li0.02)(Ta0.2Nb0.8)O-3-0.05CaZrO(3)with 2 wt.% MnO(2)addition (KNNLT-CZM) lead-free ferroelectric film heterostructures are fabricated on the La0.07Ba0.93SnO3(LBSO)-coated SrTiO3(001) substrates using pulsed laser deposition. The optical measurements show that these film heterostructures exhibit good transmittance with a maximum transmittance of similar to 80%. Temperature-dependent dielectric properties demonstrate that the KNNLT-CZM films possess a high Curie temperature (T-C) above 420 degrees C, and exhibit an orthorhombic to tetragonal phase transition at similar to 170 degrees C. Furthermore, these film heterostructures also have a large twice remnant polarization of 29.66 mu C cm(-2)and well-defined ferroelectric hysteresis loops up to 200 degrees C. The x-ray photoelectron spectra suggest that partial K elements did not enter in the lattice of the KNNLT-CZM perovskite structure and the Mn dominantly existed in the form of Mn2+. The observed good transmittance, highT(C)and excellent electrical properties of the LBSO-buffered KNNLT-CZM film heterostructures indicate that these films have great application potential in opto-electronic devices and film transistors.