Title: | Highly degenerate 2D ferroelectricity in pore decorated covalent/metal organic frameworks |
Author(s): | Zhang L; Tang C; Sanvito S; Du A; |
Address: | "School of Chemistry and Physics, Queensland University of Technology, Gardens Point Campus, Brisbane, QLD 4000, Australia. aijun.du@qut.edu.au. Centre for Materials Science, Queensland University of Technology, Gardens Point Campus, Brisbane, QLD 4000, Australia. School of Physics and CRANN Institute, Trinity College, Dublin 2, Ireland" |
ISSN/ISBN: | 2051-6355 (Electronic) 2051-6347 (Linking) |
Abstract: | "Two-dimensional (2D) ferroelectricity, a fundamental concept in low-dimensional physics, serves as the basis of non-volatile information storage and various electronic devices. Conventional 2D ferroelectric (FE) materials are usually two-fold degenerate, meaning that they can only store two logical states. In order to break such limitation, a new concept of highly degenerate ferroelectricity with multiple FE states (more than 2) coexisting in a single 2D material is proposed. This is obtained through the asymmetrical decoration of porous covalent/metal organic frameworks (COFs/MOFs). Using first-principles calculations and Monte Carlo (MC) simulations, Li-decorated 2D Cr(pyz)(2) is systematically explored as a prototype of highly degenerate 2D FE materials. We show that 2D FE Li(0.5)Cr(pyz)(2) and LiCr(pyz)(2) are four-fold and eight-fold degenerate, respectively, with sizable spontaneous electric polarization that can be switched across low transition barriers. In particular, the coupling between neighbouring electric dipoles in LiCr(pyz)(2) induces novel ferroelectricity-controlled ferroelastic transition and direction-controllable hole transport channels. Moreover, three-fold and six-fold degenerate ferroelectricity is also demonstrated in P-decorated g-C(3)N(4) and Ru-decorated C(2)N, respectively. Our work presents a general route to obtain highly degenerate 2D ferroelectricity, which goes beyond the two-state paradigm of traditional 2D FE materials and substantially broadens the applications of 2D FE compounds" |
Notes: | "PubMed-not-MEDLINEZhang, Lei Tang, Cheng Sanvito, Stefano Du, Aijun eng England 2023/04/24 Mater Horiz. 2023 Jul 3; 10(7):2599-2608. doi: 10.1039/d3mh00256j" |