磁场辅助动态自组装法制备MnCoGe基巨负热膨胀复合材料

Fabrication of MnCoGe-Based Composites with Giant Negative Thermal Expansion via Magnetic-Field-Assisted Dynamic Self-Assembly

摘要: 负热膨胀材料随温度上升表现出体积收缩特性，将其与传统正热膨胀材料结合时，可有效抵消传统正热膨胀材料因热膨胀引发的电路板变形、元件脱落的问题，因而成为实现电子器件稳定性提升的关键材料。本研究采用磁场辅助的动态自组装法，制备获得晶粒择优取向的MnCoGeSi/环氧树脂复合材料。借助扫描电子显微镜、X射线衍射仪、振动样品磁强计等仪器研究了晶体结构、显微结构和热膨胀特性。研究发现，本研究所获得MnCoGeSi/环氧树脂复合材料表现出巨负热膨胀效应，线性热膨胀系数高达−1587.6 × 10⁻⁶/K，同时不含有稀土等贵金属元素，有望应用于微电子、精密仪器等领域。

Abstract: Negative thermal expansion (NTE) materials exhibit volumetric contraction characteristics as temperature rises. When combined with conventional positive thermal expansion (PTE) materials, they can effectively counteract issues such as circuit board deformation and component detachment caused by thermal expansion in traditional materials, thus becoming key materials for enhancing the stability of electronic devices. This study employed a magnetic field-assisted dynamic self-assembly method to prepare MnCoGeSi/epoxy resin composites with preferred grain orientation. Using instruments such as scanning electron microscopy (SEM), X-ray diffractometry (XRD), and vibrating sample magnetometry (VSM), the crystal structure, microstructure, and thermal expansion properties were investigated. The results revealed that the obtained MnCoGeSi/epoxy resin composite exhibited a giant NTE effect, with a linear thermal expansion coefficient as high as −1587.6 × 10⁻⁶/K. Notably, the material does not contain rare earth or other precious metal elements, making it promising for applications in microelectronics, precision instruments, and related fields.