TbSin(n=2-13)团簇的结构、电子及磁学性质.pdf

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1、物理化学学报(WuliHuaxueXuebao1JanuaryActaPhys．一Chim．Sin．，2011，27(1)：39—4639[Article]www．whxb．pku．edu．cnTbSi，，(n=2-13)团簇的结构、电子及磁学性质白燕枝赵高峰沈学锋孙建敏王渊旭(河南大学计算材料科学研究所，河南开封475004)摘要：利用相对论密度泛函理论在广义梯度近似下研究TbSi(n=2—13)团簇的结构、稳定性、电子和磁学性质．对团簇的平均结合能、离解能、电荷转移、最高占据分子轨道(HOMO)gI~最低未占据分子轨道(LUMO)的能级差、Mulliken电荷分析和磁学性质进行了计算和

2、讨论．TbSi团簇并没有像实验推测的那样在n=l0形成嵌入式的结构．我们推断电子亲和势的急剧变化不仅与嵌入式的结构有关，而且与电子的固有稳定性相关．Mulliken电荷分析表明电荷总是从Tb原子转向Si原子．团簇的磁矩主要局域在Tb原子的周围，并且主要由，电子贡献，，电子表现出局域性并且不参与化学成键．以TbSi，。为例的分波态密度分析表明Tb与Si原子问存在很强的轨道杂化．关键词：密度泛函理论；TbSi团簇；稳定性；磁矩中图分类号：O641Geometries，ElectronicandMagneticPropertiesofTbSi，，(n=2-13)ClustersBAIYan—Zh

3、iZHAOGao—FengSHENXue—FengSUNJian—MinWANGYuan—Xu(InstituteofComputationalMaterialsScience,HenanUniversity,Kaifeng475004，HenanProvince,PR．China)Abstract：Thegeometries，stability，andelectronicandmagneticpropertiesofTbSi(n=2—13)clustersweresystematicallyinvestigatedusingrelativisticdensityfunctionaIthe

4、o~(DFT)withinthegeneralizedgradientapproximation．Theaveragebindingenergies，dissociationenergies，chargetransfer,thehighest．occupiedmolecularorbitalandthelowestunoccupiedmolecularorbitaI(HOMO．LUMO)gaps，Mullikenpopulations(MP)，andmagneticpropertieswerecalculatedandwerediscussed．TheTbSi(n=2—13)cluster

5、sdonotformencaDsuIatedstructuresatn=10．WeconcludethatthestabilityofTbSiiSconsistentwiththeencaDsulatedgeometricstructureandalsowiththeinherentelectronicstabilization．Furthermore，resultsofthecalculatedMullikenpopulationsshowthatthechargealwaystransfersfromTbtoSj．ThemagneticmomentiSIargelyIocatedonT

6、bandiSmainlypopulatedbyf-blockelectrons．ThefelectronsareveryIocalizedandtoalargeextentnotresponsibleforchemicaIbonding。Thepartialdensityofstates(PDOS)ofTbSi10showsthatthereiSstrongsphybridizationbetweenTbandSi．KeyWords：Densityfunctionaltheo~；TbSicluster；Stability；MagneticmomentSiliconclustershavea

7、ttractedgreataRentionandhavebeenidsduetothelackofsphybridizationofvalenceorbitalstudiedextensivelybyusingboththeoretical一andexpefimen—However,theencapsulationoftransitionmetalenhancesthetal一techniques．fortheiradv