Nanostructural Evolution and Magnetic Response in the Oxidation of FeCo Nanomaterials

FeCo 纳米材料氧化过程中的纳米结构演化和磁响应

• 批准号: 0804020
• 负责人: Michael McHenry
• 金额: $ 51万
• 依托单位: Carnegie-Mellon University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0804020&HistoricalAwards=false
• 关键词: Nanostructural; Evolution; Magnetic; Response; Oxidation

TECHNICAL: PI?s plan to conduct research on synthesis, structure, properties and performance relationships in magnetic nanoparticles (MNPs) having promise for applications in RF absorption, medicine, RF heating and ferrogels with unique magnetomechanical response. The intellectual merit of the work lies in: (1) furthering understanding of nanostructural evolution, oxidation products and rates of FeCo/ferrite nanocomposite materials and (2) the relationship of nanostructure (including surface and interface crystallography, metal and oxide volume fractions, thermodynamics of small particles and composition) with high frequency switching of MNPs, ferrofluids and composites. Research objectives are to develop fundamental understanding of magnetic metal/oxide core shell structures in terms of: (a) understanding the sequence of oxide formation and epitaxial relationships with polyhedral facetted magnetic FeCo nanoparticles; (b) modeling chemical partitioning occurring in oxidation and it?s role in developing surface and interfacial anisotropy in MNPs; (c) microstructural observations and magnetic properties measurements to determine anisotropy mechanisms which control Neel relaxation processes and (d) the role of Neel relaxation in the RF field activated heating of 2-phase FeCo/ferrite MNPs. This work couples with collaborations with the Pittsburgh Hillman Cancer Research Center to develop RF heating of nanoparticles for thermoablative cancer therapy and the Pittsburgh McGowan Tissue Engineering Center to develop magnetic tagging of tissue scaffolds and ferrogel magnetomechanical response for the same. NON-TECHNICAL: The potential for broad impact lies in the materials having promise in RF heating of fluids, polymers and epoxies. The work will further understanding of nanostructural development and control of magnetothermal response in these applications. Efficient point source heating of nanoparticles can be exploited for thermoablative cancer therapies and to promote attachment to tissue scaffolds if adherent, biocompatible oxide shells can be engineered and functionalized with appropriate surfactants to stabilize aqueous ferrofluids and antibodies to promote cell or tissue attachment. Work will be disseminated in publications and presentations at the MMM and materials conferences (MRS and/or TMS). Interactions and collaborations will also aid broad dissemination. We will interact with K. Hono of NRIM for field ion microscopy and Monica Sorescu of Duquesne Univ. for Mossbauer spectroscopy. Research will couple to educational initiatives. The PI?s have offered (2007) an undergraduate (UG) course ?Structure, Properties and Performance Relationships in Magnetic Materials? following a decade teaching the graduate course ?Applied Magnetism and Magnetic Materials? in the CMU Materials Science and Engineering (MSE) Dept. The PI?s have developed Powerpoint modules (2007) and distributed 350 pages of chapters through the CMU Blackboard system. These will be extended with the aim of publishing an UG Magnetic Nanomaterials text. The PI?s will continue a long history of sponsoring UG research projects (with many women and minority students), during this project.

技术：PI？我们计划对磁性纳米粒子（MNP）的合成、结构、性质和性能关系进行研究，这些纳米粒子有望在RF吸收、医学、RF加热和具有独特磁力响应的铁凝胶中应用。本论文的学术价值在于：（1）加深了对FeCo/铁氧体纳米复合材料的纳米结构演变、氧化产物和氧化速率的理解;（2）纳米结构（包括表面和界面晶体学、金属和氧化物体积分数、小颗粒热力学和组成）与MNP、铁磁流体和复合材料的高频开关的关系。研究目标是发展磁性金属/氧化物核壳结构的基本理解方面：（a）理解氧化物形成的顺序和外延与多面体刻面磁性FeCo纳米粒子的关系;（B）建模发生在氧化和它的化学分配？的作用，在开发的表面和界面各向异性的MNP;（c）微观结构观察和磁性能测量，以确定各向异性机制，控制尼尔松弛过程和（d）的作用，尼尔松弛的RF场激活加热的2相FeCo/铁氧体MNP。这项工作与匹兹堡希尔曼癌症研究中心合作开发用于热消融癌症治疗的纳米颗粒的RF加热，以及匹兹堡麦高恩组织工程中心合作开发组织支架的磁性标记和铁凝胶磁机械响应。非技术性：广泛影响的潜力在于材料在流体、聚合物和环氧树脂的射频加热中具有前景。这项工作将进一步了解纳米结构的发展和控制磁热响应在这些应用中。纳米颗粒的有效点源加热可以用于热消融癌症治疗，并促进附着到组织支架，如果粘附的，生物相容性的氧化物壳可以用适当的表面活性剂进行工程化和功能化，以稳定水性铁磁流体和抗体，以促进细胞或组织附着。工作将通过出版物和在MMM和材料会议（MRS和/或TMS）上的介绍进行传播。互动和合作也将有助于广泛传播。我们将与K互动。场离子显微镜由NRIM的Hono和穆斯堡尔光谱学由迪克讷大学的Monica Sorescu完成。研究将与教育举措相结合。私家侦探？2007年开设了本科（UG）课程？磁性材料的结构、性质和性能关系在教了十年研究生课程之后应用磁学与磁性材料CMU材料科学与工程（MSE）系私家侦探？我们已经开发了Powerpoint模块（2007年），并通过CMU黑板系统分发了350页的章节。这些将被扩展与出版UG磁性纳米材料文本的目的。私家侦探？在这个项目期间，美国大学将继续赞助大学研究项目（有许多妇女和少数民族学生）的悠久历史。