Multiphase Resistivity Model for Magnetic Nanocomposites Developed for High Frequency, High Power Transformation
Multiphase Resistivity Model for Magnetic Nanocomposites Developed for High Frequency, High Power Transformation
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为高频、高功率变换而开发的磁性纳米复合材料的多相电阻率模型
DOI：
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发表时间：
2013
影响因子：
2.1
通讯作者：
M. McHenry
中科院分区：
文献类型：
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作者：
V. DeGeorge;S. Shen;P. Ohodnicki;M. Andio;M. McHenry
新的电力转换系统有望将电网改造成统一的交互供电网络，它需要高阻软磁材料，以便能够在接近100兆赫的频率下切换磁性材料，以实现兆瓦级的电力转换。非晶态和纳米复合软磁材料在高频下具有高功率密度和低损耗的技术水平，其电阻率取决于薄带中多相的结构和空间分布。我们提出了一个适用于纳米复合材料的多相电阻率模型，该模型考虑了通过非晶态、晶态和生长抑制物壳层相的路径。我们详细介绍了：(A)非晶相、晶相和壳层相的识别；(B)考虑每个相的形态在等效电路模型中的作用；(C)关于晶相和非晶相的电阻率与Fe/Co成分的关系的双带模型；(D)用于解释早期过渡金属生长抑制剂在纳米晶相周围的壳层中由于过渡金属生长抑制剂而导致的电阻率增加的虚拟束缚态模型；以及(E)无序对非晶相电阻率的影响。在我们的模型中讨论了高频功率转换系统的实验设计和结果，包括：(A)测量截面和密度的技术，(B)四点探针和表面电阻率测量，以及(C)在富Fe和富Co系统中比较非晶态和纳米复合材料的测量。
New power conversion systems that offer promise to transform electricity grids into unified interactive supply networks require high-resistivity soft-magnetic materials to allow for switching of magnetic materials at frequencies approaching 100 kHz for power transformation in the megawatt range. Amorphous and nanocomposite soft-magnetic materials, which represent the state of the art in terms of high power densities and low losses at high frequencies, have resistivities that depend on the structures and spatial distributions of multiple phases in thin ribbons. We present a multiphase resistivity model applicable to nanocomposite materials by considering an equivalent circuit approach considering paths through an amorphous, crystalline, and growth inhibitor shell phase. We detail: (a) identification of amorphous, crystalline, and shell phases; (b) consideration of the role of the morphology of each phase in an equivalent circuit model for the resistance; (c) a two-band model for the Fe/Co composition dependence of the resistivity in crystalline and amorphous phases; (d) a virtual bound state model for resistivity to explain increased resistivity due to early transition-metal growth inhibitors in the shell surrounding the nanocrystalline phase; and (e) disorder effects on amorphous phase resistivity. Experimental design and results for systems of interest in high-frequency power transformation are discussed in the context of our model including: (a) techniques for measurements of cross-section and density, (b) four-point probe and surface resistivity measurements, and (c) measurements in Fe- and Co-rich systems comparing amorphous and nanocomposite materials.