Design of Single‐Molecule Multiferroics for Efficient Ultrahigh‐Density Nonvolatile Memories. Issue 1 (8th November 2018)

• Record Type: Journal Article
• Authors: Yang, Qing; Zhong, Tingting; Tu, Zhengyuan; Zhu, Lin; Wu, Menghao; Zeng, Xiao Cheng
• Is Part Of: Advanced science. Volume 6:Issue 1(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-11-08
• Subjects: ab initio calculations -- cross‐point multiferroic tunneling junction arrays -- multiferroic coupling -- single‐molecule ferroelectrics -- ultrahigh‐density perpendicular recording; Science -- Periodicals; 505
• DOI: 10.1002/advs.201801572
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: It is known that an isolated single‐molecule magnet tends to become super‐paramagnetic even at an ultralow temperature of a few Kelvin due to the low spin switching barrier. Herein, single‐molecule ferroelectrics/multiferroics is proposed, as the ultimate size limit of memory, such that every molecule can store 1 bit data. The primary strategy is to identify polar molecules that possess bistable states, moderate switching barriers, and polarizations fixed along the vertical direction for high‐density perpendicular recording. First‐principles computation shows that several selected magnetic metal porphyrin molecules possess buckled structures with switchable vertical polarizations that are robust at ambient conditions. When intercalated within a bilayer of 2D materials such as bilayer MoS2 or CrI3, the magnetization can alter the spin distribution or can be even switched by 180° upon ferroelectric switching, rendering efficient electric writing and magnetic reading. It is found that the upper limit of areal storage density can be enhanced by four orders of magnitude, from the previous super‐paramagnetic limit of ≈40 to ≈10 6 GB in. −2, on the basis of the design of cross‐point multiferroic tunneling junction array and multiferroic hard drive. Abstract : Single‐molecule (0D) ferroelectrics/multiferroics is proposed so every molecule can store 1 bit data at ambient conditions and a storage density up to ≈10 6 GB in. −2 can be obtained. When intercalated in bilayer of 2D materials, the magnetization can be reversed upon ferroelectric switching, rendering efficient electric writing + magnetic reading.