CAREER: Synthesis and Structure-Property Elucidation of III-V Based Magnetic Semiconductor Nanoparticles

本项目的目的是研究具有磁电耦合性质的纳米粒子的合成和物理性质表征。将研究两种类型的系统，均基于III-V半导体：(1)稀磁半导体(DMS)和(2)具有磁性：半导体界面的异质核壳纳米粒子。这种材料有望将磁性器件的信息存储能力与半导体器件的处理能力结合起来。电路的小型化有望为这种两用设备提供经济上的推动。基于III-V的纳米颗粒DMS将通过改进的锰和铁盐与铟或镓在磷或砷等致烟源存在下的共沉淀反应来制备。这些材料将使用确定纳米颗粒结构和粒度的标准技术进行表征，物理性能将通过磁化率、吸收/发光光谱和磁光耦合技术进行评估。DMS纳米粒子的结构和物理性质将与由磁性过渡金属微球核心和半导体主族微球壳层组成的异质结构纳米粒子进行比较。已经开发了用于制备过渡金属磷灰石纳米颗粒(芯)并用作铟或镓磷灰石相(壳)成核/沉淀的衬底的技术。在本研究过程中制备的稀磁和异质结构磁性半导体材料有望对专注于信息存储/传输和磁阻传感器开发的行业产生影响。因此，一个重要的教育目标是通过促进学生与当地工业之间的互动来说明材料研究与技术进步的相关性。此外，强调材料化学和纳米技术的模块将被纳入研究生和本科生的传统无机课程。

The aim of this project is to investigate the synthesis and physical property characterization of nanoparticles with coupled magnetic and electronic properties. Two types of systems will be studied, both based on III-V semiconductors: (1) Diluted magnetic semiconductors (DMS's) and (2) Heterostructured core-shell nanoparticles with a magnetic:semiconducting interface. Such materials are expected to combine the information storage ability of magnetic devices, with the processing ability of semiconductor devices. The miniaturization of circuits is expected to provide an economic impetus for such dual use devices. III-V based nanoparticle DMS's will be prepared through modified co-precipitation reactions of manganese and iron salts with indium or gallium in the presence of a pnictogen source such as phosphorous or arsenic. These materials will be characterized using standard techniques for structural and particle size determination of nanoparticles and the physical properties will be evaluated by magnetic susceptibility, absorption/luminescence spectroscopy, and coupled magnetic/optical techniques. The structural and physical properties of DMS nanoparticles will be compared to heterostructured nanoparticles consisting of a magnetic transition metal pnictide core and a semiconducting main group pnictide shell. Techniques have been developed for producing transition metal pnictide nanoparticles (cores) and to be used as substrates for the nucleation/precipitation of indium or gallium pnictide phases (shells). %%%The diluted and heterostructured magnetic semiconductor materials prepared in the course of this research are expected to impact industries focused on information storage/transmission and development of magnetoresistive sensors. Accordingly, an important educational goal is to illustrate the relevance of materials research to technological advances by fostering interactions between students and local industry. Additionally, modules emphasizing materials chemistry and nanotechnology will be incorporated into traditional inorganic courses at the graduate and undergraduate levels.