Magnetic garnet thin films: novel properties through interface and site occupancy engineering

磁性石榴石薄膜：通过界面和位点占用工程获得新特性

• 批准号: 2323132
• 负责人: Caroline Ross
• 金额: $ 48万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2323132&HistoricalAwards=false
• 关键词: Magnetic; garnet; thin; films; novel

NON-TECHNICAL SUMMARY Iron garnets are a class of oxide material with a wide range of useful magnetic properties, making them candidates for next generation solid-state memory and logic devices in which data is stored and manipulated by changing the magnetization direction of the garnet. The development of processes to grow thin films of iron garnets has led to an explosion of interest, but the great majority of this work involves single layer garnet films of simple compositions. This leaves several interesting questions unanswered, which form the core of this proposal. First, the proposal will address what magnetic properties can emerge from a multilayer garnet film made up of layers of different composition each a few atoms thick. Second, whether the type of atoms in the crystal can be controlled and arranged on the atomic scale, and what magnetic properties emerge from this ordering. An intriguing third question is whether iron garnets, which are naturally insulators, can be grown with electrical conductivity, which would facilitate electrical reading and writing of a data storage device made of garnet. The technical findings and the new material capabilities developed in this project will contribute to the development of magnetic memory, logic and other thin film devices and will be published and communicated to industrial researchers. Graduate and undergraduate students, including from a local community college, will be trained in materials design, growth and characterization. Results from the research will be incorporated into coursework and free online subjects, a public outreach activity, and into summer programs designed to increase diversity. TECHNICAL SUMMARY Engineering of site occupancy and interfaces in oxide heterostructures presents a tremendous opportunity to manipulate the properties of complex oxide thin films and to reveal new thin film phenomena. However, most work on oxide heterostructures has focused on perovskites, and there is little work on garnet oxide heterostructures. This proposal develops thin film magnetic garnet superlattices, garnet films with ordering of two or more rare earth cations within the unit cell, and conductive garnet films. These thin film structures will facilitate the introduction of electrically-controlled magnetic properties, multiferroic stacks, charge and ion conduction pathways, and new magnetic behavior promoted by symmetry breaking. The new material capabilities could form the basis of magnetic memory, logic and other thin film devices. Broader impacts include training of graduate and undergraduate students, industrial and public outreach, online teaching, and participation in summer programs designed to increase diversity.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术摘要铁石榴石是一类具有各种有用磁性特性的氧化物材料，使其成为下一代固态记忆和逻辑设备的候选者，其中通过改变石榴石的磁化方向来存储数据和操纵数据。生长铁石榴石薄膜的过程的发展导致了人们的兴趣，但是这项工作的绝大部分涉及简单构图的单层石榴石膜。这留下了几个有趣的问题，这是本提案的核心。首先，该提案将解决由多层膜组成的多层石榴石膜可以出现的磁性特性，该膜由不同的成分层组成，每个层都有几个原子厚。其次，是否可以在原子尺度上控制和排列晶体中的原子类型，以及从该顺序出现的磁性特性。一个有趣的第三个问题是，自然是绝缘体的铁石榴石是否可以通过电导率生长，这将有助于用石榴石制成的数据存储设备的电读写和写作。该项目中开发的技术发现和新的材料功能将有助于磁性记忆，逻辑和其他薄膜设备的发展，并将发布并传达给工业研究人员。包括当地社区学院在内的研究生和本科生将接受材料设计，成长和特征的培训。该研究的结果将纳入课程工作和免费的在线主题，公共外展活动，以及旨在增加多样性的夏季计划中。氧化物异质结构中现场占用和界面的技术摘要工程提供了一个巨大的机会，可以操纵复杂的氧化物薄膜的特性并揭示新的薄膜现象。但是，大多数关于氧化物异质结构的工作都集中在钙壶上，并且在石榴石氧化物异质结构上几乎没有工作。该提案开发了薄膜磁石榴超晶格，石榴石膜，并在单位电池内订购两个或多个稀有的土阳离子以及导电石榴石膜。这些薄膜结构将有助于引入电控制的磁性特性，多效性堆栈，电荷和离子传导途径，以及通过对称性破坏促进的新磁性行为。新的材料功能可以构成磁记忆，逻辑和其他薄膜设备的基础。更广泛的影响包括培训研究生和本科生，工业和公共外展，在线教学以及参与旨在提高多样性的夏季计划的参与。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子来评估的支持，并具有更广泛的影响。