Transition Metal Pnictide Nanoparticles: Synthesis and Assembly of Novel Magnetic Materials

过渡金属磷化物纳米粒子：新型磁性材料的合成与组装

• 批准号: 0701161
• 负责人: Stephanie Brock
• 金额: $ 36万
• 依托单位: Wayne State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2011-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0701161&HistoricalAwards=false
• 关键词: Transition; Metal; Pnictide; Nanoparticles; Synthesis

Fundamental issues pertaining to the exploitation of magnetic nanomaterials in devices will be explored for a series of transition metal pnictide phases with promising attributes for spintronic or magnetic data storage applications. The fundamental factors that underpin the nucleation and growth of manganese arsenide (MnAs) and manganese phosphide (MnP) will be elucidated using arrested precipitation strategies with conventional and microwave heating. Once prepared, the role of particle size on the first-order phase transition in MnAs, and the effect of different kinds of anisotropy on the coercive properties of MnP, will be studied. The factors that control product stoichiometry in iron phosphides (FexP where x=1, 2, or 3) will be discerned by a detailed study of reactant stoichiometry, reactant activity, temperature and time. Single-phase nanoparticulate (FexP) samples will then be used to determine the effects of short physical length scales on complex magnetic ordering and coercivity. This work will also explore the condensation of discrete MnP nanoparticles into gel-structures and the influence of the aggregate and pore structure on dipole-dipole interactions between discrete particles. In the course of pursuing this research, graduate and undergraduate student researchers will develop critical thinking skills and proficiency in scientific writing and communication, as well as learn cutting-edge research techniques, including electron microscopy.%%%Due to their small footprint and size-tunable properties, nanomaterials promise to revolutionize a wide range of technologies from computer processing and data storage to biological imaging of disease states. However, the exploitation of nanomaterials in actual devices is limited by progress in a number of fundamental areas. These include: methods for preparing single-phase, low-polydispersity samples of particles with control of shape and size; methods for assembling particles into functional architectures; quantification of the relationship between the observed physical properties and the size, shape, and composition of the material; and evaluation of the influence of particle-particle interactions in 3 D architectures. This project will address these fundamental issues in the context of a series of transition metal pnictide phases with promising attributes for spintronic or magnetic data storage applications, but which have not been systematically evaluated on the nanoscale: MnAs, MnP, and Fe-P (FeP, Fe2P, Fe3P). In the course of pursuing this research, graduate and undergraduate students will develop critical thinking skills and proficiency in scientific writing and communication, as well as learning cutting-edge research techniques and how to work in an interdisciplinary team. So prepared, these students will be among the vanguard of new researchers employed in developing the next generation of advanced technologies.

关于在器件中开发磁性纳米材料的基本问题，将针对一系列具有自旋电子学或磁性数据存储应用前景的过渡金属相进行探索。采用常规加热和微波加热的阻挡沉淀法，将阐明支撑砷化锰(MNAs)和磷化锰(MNP)成核和生长的基本因素。一旦制备成功，将研究颗粒尺寸对MNAs一级相变的影响，以及不同类型的各向异性对MNP矫直性能的影响。控制磷化铁(FexP，其中x=1、2或3)中产品化学计量的因素将通过对反应物化学计量、反应物活性、温度和时间的详细研究来识别。然后将使用单相纳米颗粒(FexP)样品来确定短物理长度尺度对复磁有序和矫顽力的影响。这项工作还将探索离散的MNP纳米粒子凝聚成凝胶结构，以及聚集体和孔结构对离散粒子之间偶极-偶极相互作用的影响。在从事这项研究的过程中，研究生和本科生研究人员将培养批判性思维能力和科学写作和交流的熟练程度，并学习包括电子显微镜在内的尖端研究技术。%由于其占地面积小和尺寸可调的特性，纳米材料有望彻底改变从计算机处理和数据存储到疾病状态的生物成像的广泛技术。然而，纳米材料在实际设备中的开发受到一些基本领域进展的限制。这些包括：控制形状和尺寸的单相、低多分散性颗粒样品的制备方法；将颗粒组装成功能结构的方法；观察到的物理性质与材料的尺寸、形状和组成之间的关系的量化；以及三维结构中颗粒-颗粒相互作用的影响评估。本项目将在一系列过渡金属相的背景下解决这些基本问题，这些相具有有望用于自旋电子或磁数据存储应用的属性，但尚未在纳米尺度上进行系统评估：MnAs、MnP和Fe-P(FeP、Fe2P、Fe3P)。在从事这项研究的过程中，研究生和本科生将培养批判性思维能力和科学写作和沟通的熟练程度，并学习尖端研究技术和如何在跨学科团队中工作。经过这样的准备，这些学生将成为开发下一代先进技术的新研究人员的先锋。