Ge_nEu(n=1-13)团簇的结构、电子及磁性质(英文)

利用密度泛函理论在广义梯度近似下研究了GenEu(n=1-13)团簇的生长模式和磁性.结果表明:对于GenEu(n=1-13)团簇的基态结构而言,没有Eu原子陷入笼中.这和SinEu以及其它过渡金属掺杂半导体团簇的生长模式不同.除GeEu团簇外,GenEu(n=2-13)团簇的磁矩均为7μB.团簇的总磁矩与Eu原子的4f轨道磁矩基本相等.Ge、Eu原子间的电荷转移以及Eu原子的5d、6p和6s间的轨道杂化可以增强Eu原子的局域磁矩,却不能增强团簇总磁矩.

Structural, Electronic and Magnetic Properties of the GenEu (n=1-13) Clusters

The growth pattern and magnetic properties of the GenEu (n=1-13) clusters have been investigated using the density functional theory within the generalized gradient approximation. For all the ground state structures of the GenEu (n=1-13) clusters, Eu atom always prefers to cap on the surface of the germanium frame, which is different from the growth pattern of the SinEu cluster and other transition metal-doped semiconductor clusters. The total magnetic moments of the GenEu clusters have a constant value (7μB) except the GeEu cluster. The total magnetic moment of the GenEu clusters are mostly equal to the local magnetic moment of the 4f state of the Eu atom. Although charge transfer between Ge and Eu as well as hybridization among the Sd, 6p, and 6s states of Eu atom can enhance the local magnetic moment of Eu, it does not enhance the total magnetic moment of the GenEu clusters.