Be_nLa(n=1—18)团簇的结构、电子性质和磁性

Structure,electronic properties and magnetism of La-doped Be clusters Be_nLa

采用基于密度泛函理论的第一性原理方法,在多种初始构型下充分考虑自旋多重度,研究了BenLa团簇的平衡几何结构、电子性质和磁性.结果表明:BenLa团簇的基态附近有许多能量非常接近的同分异构体,说明该团簇结构较复杂,对其基态的寻找极具挑战性.BenLa团簇具有磁性且稳定性远高于Ben+1团簇,由此可知通过选择合适的掺杂元素可能得到高稳定性的磁性团簇.Be17La团簇特别稳定且能隙与主团簇的能隙相当.体系的磁矩主要来自外层未成对的价电子且La元素的贡献是主要的,除BeLa,Be3La团簇的磁矩为3μB外,其余的都为1μB.

With many kinds of initial configurations and spin multiplicities taken in full consideration, the first principile method based on density-functional theory （DFT） has been employed to study the equilibrium geometries, electronic properties and magnetism of Ben La （ n = 1-18）. Our results showed that there are many isomers with extremely close energies near the ground state, thus the cluster is very complex, making the ground state seek quite challenging. The Ben La has magnetism and its stability is far higher than that of Ben ＋ 1, indicating that one can acquire magnetic clusters with higher stabilities by choosing the proper doping atom. The Be17 La is specially stable and its gap between the highest occupied and the lowest unoccupied molecular orbitals is quite the same as that of the host cluster. The magnetic moment in Be~ La cluster system comes mainly from the outer layer unpaired valence electrons and the La element＇s contribution. The magnetic moment of Ben La is 1μB except that of BeLa and Be3La, which is 3μB.