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Hybrid Improper Ferroelectricity in Multiferroic Superlattices: Finite‐Temperature Properties and Electric‐Field‐Driven Switching of Polarization and Magnetization
Author(s) -
Xu Bin,
Wang Dawei,
Zhao Hong Jian,
Íñiguez Jorge,
Chen Xiang Ming,
Bellaiche Laurent
Publication year - 2015
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201501113
Subject(s) - multiferroics , ferroelectricity , condensed matter physics , superlattice , magnetization , materials science , polarization density , electric field , dielectric , polarization (electrochemistry) , phase transition , magnetic field , physics , optoelectronics , quantum mechanics , chemistry
The so‐called hybrid improper ferroelectricity (HIF) mechanism allows to create an electrical polarization by assembling two nonpolar materials within a superlattice. It may also lead to the control of the magnetization by an electric field when these two nonpolar materials are magnetic in nature, which is promising for the design of novel magneto‐electric devices. However, several issues of fundamental and technological importance are presently unknown in these hybrid improper ferroelectrics. Examples include the behaviors of its polarization and dielectric response with temperature, and the paths to switch both the polarization and magnetization under electric fields. Here, an effective Hamiltonian scheme is used to study the multiferroic properties of the model superlattice (BiFeO 3 ) 1 /(NdFeO 3 ) 1 . Along with the development of a novel Landau‐type potential, this approach allows to answer and understand all the aforementioned issues at both microscopic and macroscopic levels. In particular, the polarization and dielectric response are both found to adopt temperature dependences, close to the phase transition, that agree with the behavior expected for first‐order improper ferroelectrics. And most importantly, a five‐state path resulting in the switching of polarization and magnetization under an electric field, via the reversal of antiphase octahedral tiltings, is also identified.