Thickness-Dependent Evolution of Piezoresponses and Stripe 90° Domains in (101)-Oriented Ferroelectric PbTiO3 Thin Films

• DOI: 10.1021/acsami.8b07206
• Publication Date: 2018-07-03T14:29:35Z
• Authors: Yanpeng Feng; Yunlong Tang; Desheng Ma; Yinlian Zhu; Minjie Zou; Mengjiao Han; Jinyuan Ma; Xiuliang Ma
• Keywords: 0103 physical sciences; 02 engineering and technology; 0210 nano-technology; 01 natural sciences; 0104 chemical sciences

High-index ferroelectric films as (101)-orientated ones exhibit enhanced dielectric responses, piezoelectric and exotic switching behaviors, which are potential candidates for applications in memories capacitors. However, possible domain patterns wall structures (101)-oriented thin still elusive, results difficulties understanding the origin further modulating their special properties. In this work, a series of PbTiO3 (PTO) with 35, 50, 60, 70 nm thickness were grown on (LaAlO3)0.29(SrTa1/2Al1/2O3)0.71 (LSAT(101)) substrates by pulsed laser deposition investigated both piezoresponse force microscopy (PFM) (scanning) transmission electron ((S)TEM). PFM measurements reveal that periodic stripe domains dominant 50 thick PTO films. Besides domains, a/c appear more than 60 nm. A thickness-dependent evolution amplitude indicates demonstrate superior piezoresponse. Electron diffraction contrast analysis clarify all these contain 90° domains. The periods increase film following Kittel's law. Aberration-corrected STEM imaging reveals have an alternate arrangement wide narrow c polarization directions along [100] c1 [001̅] c2 forming "head-to-tail" configuration. Further strain uniform distributions distinct lattice rotations around walls. It is proposed high-density main contributor to behavior. These expected provide useful information understand thus facilitate modulation properties applications.