Control of surface structures and functionalities in perovskite-type ferroelectric oxides and their potential applications

Abstract

Over the past decades, exploration and artificial control of the surface and interfacial structure of the materials have played an important role in chemical catalyzing, energy conversion, information storage and medical field, and thus the finding of suitable materials with controllable surface/interface properties has attracted intense interest in recent years. Perovskite-type ferroelectric oxides are considered to be one of the most promising functional materials due to their intrinsic, non-volatile, reversible spontaneous polarization and controllable polar surface with high charge density. The investigating of the interaction between polarization and surface structure of perovskite-type ferroelectric oxide is very important for understanding the surface (interface) energy conversion, regulating the adsorption and desorption on the surface, controlling interfacial chemical reaction, and designing stable low-power electronic devices. In this paper, we summarize the theoretical mechanism and potential applications of the surface structures and functionality in perovskite-type ferroelectric oxide from three aspects. Firstly, we describe the inseparable relationship between the stabilized ferroelectric phase and surface structure of ferroelectric material, and illustrate the formation mechanism of complex surface structure of perovskite-type ferroelectric oxide. In order to reduce the surface energy to stabilize the polar surface of the material, perovskite-type ferroelectric oxide always needs to absorb foreign charged particles, change the stoichiometry and conduct electron orbital hybridization or surface relaxation, etc., which will cause the complexity of the surface structure of ferroelectric. Secondly, we outline the influence of ferroelectric polarization on the surface structure of ferroelectric and the behavior of changing ferroelectric polarization by controlling surface structure through adjusting the external environment, which provides an important basis for the subsequent regulation of the surface performance and functionality of perovskite-type ferroelectric oxide. Finally, we introduce the utilization of the controllable physical and chemical properties of ferroelectric surface (interface) into large area and into nanoscale (nanodomain), which has bright application prospects in many frontier fields, including non-volatile memory system, cell proliferation, microfluidic control system, catalysis, optical device and photodetector and so on. Furthermore, considering the limitations of current scientific research about the ferroelectric surface, we put forward the prospects for the future development of the ferroelectric material in the areas of information storage, controllable chemical reactions and new energy conversion.