Tuning Piezoelectricity via Thermal Annealing at a Freestanding Ferroelectric Membrane
Lu Han, Xinrui Yang, Yingzhuo Lun, Yue Guan, Futao Huang, Shuhao Wang, Jiangfeng Yang, Chenyi Gu, Zhengbin Gu, Lisha Liu, Yaojin Wang, Peng Wang, Jiawang Hong, Xiaoqing Pan, Yuefeng Nie
Abstract
Tuning the ferroelectric domain structure by a combination of elastic and electrostatic engineering provides an effective route for enhanced piezoelectricity. However, for epitaxial thin films, the clamping effect imposed by the substrate does not allow aftergrowth tuning and also limits the electromechanical response. In contrast, freestanding membranes, which are free of substrate constraints, enable the tuning of a subtle balance between elastic and electrostatic energies, giving new platforms for enhanced and tunable functionalities. Here, highly tunable piezoelectricity is demonstrated in freestanding PbTiO 3 membranes, by varying the ferroelectric domain structures from c -dominated to c / a and a domains via aftergrowth thermal treatment. Significantly, the piezoelectric coefficient of the c / a domain structure is enhanced by a factor of 2.5 compared with typical c domain PbTiO 3 . This work presents a new strategy to manipulate the piezoelectricity in ferroelectric membranes, highlighting their great potential for nano actuators, transducers, sensors and other NEMS device applications.