内嵌镧原子的磁性硅纳米线的第一性原理研究

First-principles study on the lanthanide endohedral magnetic Si nanowire

基于密度泛函理论,系统研究了由两个La@Si16组装而成的高度稳定的管状二聚体La2@Si32团簇.电子结构分析显示,内嵌La原子诱导的类sp2杂化对于提高管状Si32的稳定性至关重要.Mülliken布局分析显示,La2@Si32的总磁矩为2μB,主要来源于两个La原子和第三、第六层的八个Si原子;电荷是由Si原子转移到了La原子上.此外,通过连接一系列La2@Si32单体而获得了一类组装的硅纳米线La@SiNW,研究结果显示La@SiNW具有金属导电特性,其总磁矩为2μB.上述特征暗示具有磁性的La2@Si32和La@SiNW可能在自旋电子器件和高密度磁记录材料方面具有潜在的应用前景.

A class of exceptionally stable dimer consisting of two endohedral La@Si16 cages,a tubular cluster La2@Si32,has been investigated systematically by using density functional theory.Electronic structure analysis demonstrates that the La atom is crucial to stabilizing the tubular Si32 due to the sp2-like hybridizations induced by the endohedral La atoms.Mülliken population analysis suggests that the total magnetic moment of La2@Si32 is 2μB,the contributions to magnetism mainly come from the two La atoms and eight Si atoms in the third and the sixth layers.The charge always transfers from the each Si atom to La atoms.Furthermore,a type of assembled Si nanowire La@SiNW,constructed by concatenating a series of La2@Si32 units,is gained.It is found that the La@SiNW is of metallic conductive character and has the total magnetic moment of 2μB.The above characteristics suggest that the magnetic La2@Si32 and La@SiNW may have potential applications in the fields of the future spintronic devices and high-density magnetic storage materials.