Substrate-dependent ferroelectric and dielectric properties of Mn doped Na0.5Bi0.5TiO3 thin films derived by chemical solution decomposition

摘要

Na0.5Bi0.5(Ti0.98Mn0.02)O-3 (NBTMn) thin films have been fabricated on Pt/TiO2/SiO2/Si and LaNiO3 (LNO)/Si substrates via chemical solution decomposition. The microstructure, ferroelectric and dielectric properties were investigated. Both films on different substrates can be crystallized into the phase-pure perovskite structures. The NBTMn thin film deposited on Pt/TiO2/SiO2/Si substrate shows random orientation with (100) and (110) diffraction peaks, while the sample on LNO/Si exhibits preferred orientation with strong diffraction peaks of (100). The NBTMn thin film deposited on LNO/Si substrate exhibits a denser and smoother microstructure. Compared with the round shaped polarization-electric field hysteresis loops of NBTMn on Pt/TiO2/SiO2/Si substrate, the enhanced ferroelectric property can be observed in NBTMn thin film fabricated on LNO/Si with a remanent polarization (P-r) of 10.2 mu C/cm(2) due to the reduced leakage current. The dielectric tunabilities of two films increase gradually with the increasing of applied voltage, and the sample on LNO/Si substrate has a relatively larger dielectric tunability with 20% at 14 V and 1 MHz. (C) 2016 Elsevier B.V. All rights reserved.