Self-Assembled Epitaxial Ferroelectric Oxide Nanospring with Super-Scalability.

Guohua Dong,Zuo‐Guang Ye,Xueyun Wang,Zhongqiang Hu,Junwei Zhang,Zhuangde Jiang,Yongqi Dong,Jiawang Hong,Yanan Zhao,Dan Xian,Ruobo Peng,Haixia Liu,Yong Peng,Bin Peng,Houbing Huang,Qi Mao,Zhenlin Luo,Ziyao Zhou,Changqing Guo,Ming Liu,Zhiguang Wang,Haijun Wu,Yue Hu,Wei Ren

doi:10.1002/adma.202108419

Abstract

Oxide nanosprings have attracted many research interests because of their anticorrosion, high-temperature tolerance, oxidation resistance, and enhanced-mechanic-response from unique helix structures, enabling various applications like nanomanipulators, nanomotors, nanoswitches, sensors, and energy harvesters. However, preparing oxide nanosprings is a challenge for their intrinsic lack of elasticity. Here, an approach for preparing self-assembled, epitaxial, ferroelectric nanosprings with built-in strain due to the lattice mismatch in freestanding La0.7 Sr0.3 MnO3 /BaTiO3 (LSMO/BTO) bilayer heterostructures is developed. It is found that these LSMO/BTO nanosprings can be extensively pulled or pushed up to their geometrical limits back and forth without breaking, exhibiting super-scalability with full recovery capability. The phase-field simulations reveal that the excellent scalability originates from the continuous ferroelastic domain structures, resulting from twisting under co-existing axial and shear strains. In addition, the oxide heterostructural springs exhibit strong resilience due to the limited plastic deformation nature and the built-in strain between the bilayers. This discovery provides an alternative way for preparing and operating functional oxide nanosprings that can be applied to various technologies.

Highlights

Nano-springs can find broad potential applications in sensors, electronics, actuators, and other electromechanical nanodevices[1,2,3,4,5] due to their unique spiral structures, elongation/compression, elasticity and resilience, and harmonic vibration properties
Synchrotron-based reciprocal space mapping (RSM) shows asymmetric RSM (-103) reflections with the four-fold splits, which verifies the fully epitaxial growth of LSMO, BTO, SAO, and STO (Fig. 1b), comparable with the results obtained from symmetric RSM (002) reflections and θ-2θ scans (Supplementary Fig.S1 and S2)
While the LSMO/BTO heterostructures were transferred onto the polydimethylsiloxane (PDMS) support, they broke and self-assembled into regular nanostripes along the [110] crystallographic direction of BTO (Fig. 1d and f)

Summary

Introduction

Nano-springs can find broad potential applications in sensors, electronics, actuators, and other electromechanical nanodevices[1,2,3,4,5] due to their unique spiral structures, elongation/compression, elasticity and resilience, and harmonic vibration properties. We developed an approach for preparing self-assembled, epitaxial, ferroelectric nanosprings with built-in strain due to the lattice mismatch in freestanding La0.7Sr0.3MnO3/BaTiO3 (LSMO/BTO) bilayer heterostructures.

Results

Conclusion