title: Novel lead-free ferroelectric film by ultra-small Ba0.8Sr0.2TiO3nanocubes assembled for a large electrocaloric effect.
abstract: A giant electrocaloric effect (ECE) can be achieved in ferroelectric thin films, which demonstrates the applications of thin films in alternative cooling. However, electrocaloric thin films fabricated by conventional techniques, such as the pulsed laser deposition or sol-gel methods, may be limited by high costs, low yield and their dependence on substrates. In this study, we present a new bottom-up strategy to construct electrocaloric Ba0.8Sr0.2TiO3thin films by assembling precisely designed building blocks of ferroelectric nanocubes, which is supported by detailed structural characterization. Moreover, it is found that our assembled Ba0.8Sr0.2TiO3films differ remarkably from both individual Ba0.8Sr0.2TiO3NPs and bulk Ba0.8Sr0.2TiO3ceramics in terms of new collective ferroelectric properties, including superior and diffused permittivity constants and polarization-electric field loops. Benefiting from these unique ferroelectric properties, a giant ECE (9.1 K) over a broad temperature range (20 °C to 60 °C) is achieved, which is very large in the lead-free oxide film. Clearly, this bottom-up strategy provides a promising pathway for developing high electrocaloric effect devices.
authors.affiliation: Frontier Institute of Science and Technology, State Key Laboratory for Mechanical behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China. yaodongy@mail.xjtu.edu.cn.
authors.forename: Ran
authors.initials: R
authors.lastname: Su
authors.affiliation: Frontier Institute of Science and Technology, State Key Laboratory for Mechanical behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China. yaodongy@mail.xjtu.edu.cn.
authors.forename: Dawei
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Laboratoire Structures, Propriétés et Modélisation des Solides, CentraleSupélec, CNRS-UMR8580, Université Paris-Saclay, Grande Voie des Vignes, Châtenay-Malabry Cedex 92295, France.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an, 710049, China.
authors.forename: Jiangbo
authors.initials: J
authors.lastname: Lu
authors.affiliation: Frontier Institute of Science and Technology, State Key Laboratory for Mechanical behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China. yaodongy@mail.xjtu.edu.cn.
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Frontier Institute of Science and Technology, State Key Laboratory for Mechanical behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China. yaodongy@mail.xjtu.edu.cn.
authors.forename: Linglong
authors.initials: L
authors.lastname: Li
authors.affiliation: Frontier Institute of Science and Technology, State Key Laboratory for Mechanical behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China. yaodongy@mail.xjtu.edu.cn.
authors.forename: Jihong
authors.initials: J
authors.lastname: Bian
authors.affiliation: Frontier Institute of Science and Technology, State Key Laboratory for Mechanical behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China. yaodongy@mail.xjtu.edu.cn.
authors.forename: Ming
authors.initials: M
authors.lastname: Wu
authors.affiliation: Frontier Institute of Science and Technology, State Key Laboratory for Mechanical behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China. yaodongy@mail.xjtu.edu.cn.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Lou
authors.affiliation: Frontier Institute of Science and Technology, State Key Laboratory for Mechanical behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China. yaodongy@mail.xjtu.edu.cn.
authors.forename: Yaodong
authors.initials: Y
authors.lastname: Yang