Anti-ferroelectric materials for non-volatile memory applications

全球对数字数据存储的需求正在呈指数级增长。IBM估计，地球上每天产生2.5万亿个数字数据字节(2.5x1018字节=2.5艾字节=25亿GB)。这种巨大的数字数据存储需求有两个后果：a)数据存储服务器的功耗增加；b)永远需要开发数据存储技术，以降低成本和功耗来满足日益增长的需求。这些问题促使对固态存储器的研究加速，在几乎所有消费电子产品和便携式设备中，固态存储器正在迅速取代传统的硬盘驱动器。2016年12月和2017年1月，爱荷华州立大学旅行补助金的首席研究员(PI)和他的合作研究员首次提出并演示了块状反铁电陶瓷材料中的一种新的固态记忆效应[1-3]。虽然这是一个非常有希望的发现，但作者指出了一些需要进一步研究的问题，包括显著限制从存储单元恢复的信号的松弛过程。此外，人们承认，这种效应在块状反铁电材料中观察到，而固态存储芯片是基于薄膜的。这笔数额不大的EPSRC海外旅行补助金(&lt；GB 15k)旨在迅速解决这些问题，方法是安排五周的旅行，前往两个国家的三家海外机构进行反铁电材料的专门实验，并获得关键技能，这些技能将增进我们对反铁电材料的理解，并有可能加速这项研究的商业化。通过与加州西部数据(WD)数据存储技术领域的领先研究人员、爱荷华州立大学(ISU)反铁电材料物理学领域的领先研究人员以及布加勒斯特国家材料物理研究所(NIMP)的穆斯堡尔谱专家合作，PI将有机会研究反铁电薄膜中的驰豫过程和记忆效应。此外，PI还将获得有价值的新实验技术，如：利用原位透射电子显微镜(ISU)、器件结构/固态存储单元测试(WD)和穆斯堡尔谱(NIMP)制备反铁电材料及其磁畴成像。这是一笔物有所值的低风险/高收益EPSRC旅行补助金，具有巨大的学术、社会和经济影响潜力。[1]。谭锡文，四态反铁电随机存取存储器，电子器件通讯(2016)。M·沃普森，G·卡伦图，谭锡安，反铁电材料中的极化反转与记忆效应，《材料手稿》第128卷，61-(2017)。谭锡文，反铁电体中的非平衡极化动力学，物理评论B 96(1)，014104(2017年)

The worldwide demand for digital data storage is increasing exponentially. IBM estimates that 2.5 quintillion of digital data bytes are produced every day on Earth (2.5 x 1018 bytes = 2.5 Exabytes = 2.5 billion Gigabytes). This huge digital data storage demand has two consequences: a) the increased power consumption of data storage servers; b) the perpetual need to develop data storage technologies that meet the increasing demand at reduced cost and power consumption. These issues have prompted the acceleration of research into solid-state memories, which are fast replacing traditional magnetic hard disc drives in almost all consumer electronics and portable devices. In Dec. 2016 and Jan. 2017, the principal investigator (PI) of this travel grant and his co-investigator from Iowa State University, proposed and demonstrated, for the first time, a novel solid-state memory effect in bulk anti-ferroelectric ceramic materials [1-3]. Although this is a very promising discovery, the authors pointed out a few issues that required further investigation, including a relaxation process that significantly limited the signal recovered from a memory cell. In addition, it was acknowledged that the effect was observed in bulk anti-ferroelectric materials, while solid-state memory chips are based on thin films. This modest EPSRC overseas travel grant (< £15k), seeks to swiftly redress these issues by facilitating five weeks travel to three overseas institutions, in two countries, in order to perform specialized experiments on anti-ferroelectric materials and to acquire key skills that will advance our understanding of anti-ferroelectric materials and potentially accelerate the commercialization of this research. By working with leading researchers in the field of data storage technologies at Western Digital (WD) - California, physics of anti-ferroelectric materials at Iowa State University (ISU) and experts in Mossbauer Spectroscopy at the National Institute of Materials Physics (NIMP) in Bucharest, the PI will have the opportunity to study relaxation processes and memory effect in anti-ferroelectric thin films. In addition, the PI will acquire valuable new experimental skills such as: fabrication of anti-ferroelectric materials and their domains imaging using in-situ Transmission Electron Microscopy (ISU), device architecture / solid state memory cell testing (WD) and Mossbauer Spectroscopy (NIMP). This is an excellent value for money low-risk / high-gain EPSRC travel grant, with huge potential for academic, societal and economic impacts. [1]. M. Vopson, X. Tan, 4-state anti-ferroelectric random access memory, Electron Device Letters (2016).[2]. M. Vopson, G. Caruntu, X. Tan, Polarization reversal and memory effect in anti-ferroelectric materials, Scripta Materialia vol. 128, 61-64 (2017).[3]. M. Vopson, X. Tan, Nonequilibrium polarization dynamics in antiferroelectrics, Physical Review B 96 (1), 014104 (2017)