EAGER: Multifunctional devices based on coupled phase transitions in antiferromagnetic semiconductors

EAGER：基于反铁磁半导体耦合相变的多功能器件

• 批准号: 1200014
• 负责人: Leonid Rokhinson
• 金额: $ 10.46万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-15 至 2014-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1200014&HistoricalAwards=false
• 关键词: EAGER; Multifunctional; devices; based; coupled

Intellectual Merit of the project is to demonstrate key technology toward development of novel multifunctional devices based on antiferromagnetic (AF) semiconductors. The proposed devices will combine non-volatile magnetic memory with electronic transistor functionality in a single device, thus resolving current dichotomy between logic circuitry and memory implementations. For operation devices will utilize phase transitions which, combined with sup-ps intrinsic magnetization dynamics, will offer THz speeds in both functionality domains. The devices will also have a potential to improve on basic transistor switching characteristics if gate-induced coupled phase transitions are realized. Finally, these magnetic devices will have no fringing fields, thus allowing high density packaging. The proposed devices are metal-oxide-AF-semiconductor field-effect transistors, MOS(AF)FET, where mobile carriers are induced into an AF semiconductor by electrostatic gating. This functionality will enable electrical detection of the magnetization axis in collinear AF materials for the first time. At high carrier concentrations we expect a succession of metal-insulator, antiferromagneticferromagnetic (AF-FM) and structural phase transitions, which will allow electrostatic control of both electrical and magnetic properties of the AF host. Of a special interest for fast memory recording is a possibility to rotate the magnetization axis in multi-axis collinear AF by means of AF-FM phase transition, where magnetic torque will be generated by a few tesla intrinsic exchange fields. For prototype demonstrations we will focus on NiO. NiO is a technologically relevant room temperature collinear AF semiconductor which can be epitaxially grown on readily available MgO substrates. The focus of EAGER proposal is to fabricate and characterize NiO?based MOS(AF)FET and to demonstrate electrical detection of AF magnetization axis. The broader impact of this project will be development of the enabling technology for the investigation of electrostatically-induced AF-FM phase transition, study of fundamental physics of coupled phase transitions, and analysis of magnetization dynamics in AF semiconductors. A student working on the project will be involved in a truly interdisciplinary research, bridging fields of material science, semiconductor physics and magnetism. The PI is developing a new graduate course on physics of magnetic semiconductors which will be disseminated to a wider audience using NSF-sponsored nanoHUB.org facility at Purdue University.

该项目的智力价值是展示基于反铁磁（AF）半导体的新型多功能器件开发的关键技术。所提出的器件将在单个器件中结合联合收割机非易失性磁存储器和电子晶体管功能，从而解决了当前逻辑电路和存储器实现之间的二分法。 对于操作设备将利用相变，其与超ps固有磁化动力学相结合，将在两个功能域中提供THz速度。如果实现栅极感应耦合相变，这些器件也将有可能改善基本晶体管的开关特性。最后，这些磁性器件将没有边缘场，从而允许高密度封装。提出的器件是金属氧化物AF半导体场效应晶体管，MOS（AF）FET，其中移动的载流子通过静电门控被引入AF半导体。该功能将首次实现共线AF材料中磁化轴的电检测。 在高载流子浓度下，我们预计会出现一系列的金属-绝缘体、反铁磁铁磁（AF-FM）和结构相变，这将允许静电控制AF主机的电和磁特性。对于快速存储器记录特别感兴趣的是通过AF-FM相变在多轴共线AF中旋转磁化轴的可能性，其中将由几个特斯拉的本征交换场产生磁转矩。 对于原型演示，我们将专注于NiO。NiO是一种技术上相关的室温共线AF半导体，其可以在容易获得的MgO衬底上外延生长。EAGER建议的重点是制造和表征NiO？的MOS（AF）FET，并演示AF磁化轴的电检测。 该项目的更广泛的影响将是开发用于研究静电诱导AF-FM相变的使能技术，研究耦合相变的基础物理，以及AF半导体中磁化动力学的分析。 从事该项目的学生将参与真正的跨学科研究，桥接材料科学，半导体物理和磁学领域。PI正在开发一门关于磁性半导体物理学的新研究生课程，该课程将使用普渡大学NSF赞助的nanoHUB.org设施向更广泛的受众传播。