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采用基于密度泛函理论的第一性原理方法,研究了密排六方结构的Co10纳米线填充(12,0)硼氮纳米管(BNNT)的结构稳定性、电子性质和磁性质。完全弛豫后的Co10/BNNT(12,0)复合体系,外围的BNNT沿着Co10纳米线的三重旋转对称轴变成了近似正三角形的结构。复合体系Co10/BNNT(12,0)的形成是自发地放热过程。电荷由Co10纳米线转移到BNNT上。Co10纳米线最外层的Co原子与其近邻的N原子形成的Co-N键具有极性共价键特征。Co10纳米线封装入BNNT后,其平均磁矩有所减小,但相对于纯BNNT,Co10/BNNT(12,0)体系具有较大的磁矩值。同时复合体系Co10/BNNT(12,0)表现出明显的半金属特征。因此这种稳定的纳米复合体系在高密度磁数据记录设备及自旋电子学器件等方面具有重要的应用价值。
The first-principle method based on density functional theory (DFT) is used to study the structural stability, electronic properties and magnetic properties of close-packed hexagonal structured Co10 nanowire-filled (12,0) boron nitride nanotubes (BNNTs). After the complete relaxation of the Co10 / BNNT (12,0) composite system, the peripheral BNNTs turn into an approximately equilateral triangle structure along the triple rotational symmetry axis of the Co10 nanowire. The formation of the composite system Co10 / BNNT (12,0) is a spontaneous exothermic process. The charge is transferred from the Co10 nanowire to the BNNT. The Co-N bond formed by Co atoms in the outermost layer of Co10 nanowires and their adjacent N atoms has polar covalent bond. The average magnetic moment of Co10 nanowire encapsulated into BNNT is reduced, but the magnetic moment of Co10 / BNNT (12,0) system is larger than that of pure BNNT. At the same time, the composite system Co10 / BNNT (12,0) showed obvious semi-metallic characteristics. Therefore, this stable nanocomposite system has important applications in high-density magnetic data recording devices and spintronic devices.