TinO2和TinO2-(n=1-10)团簇的几何结构、电子和磁性质

基于密度泛函理论(DFT)的B3LYP方法, 研究了Ti_nO₂和Ti_nO₂^- (n=1-10)团簇的几何结构、电子结构以及磁性. 结果表明, 两个氧以分离的原子状态吸附在金属团簇的表面, 呈现出以一个钛原子为中心的O-Ti-O 的相邻吸附形式. 中性团簇和阴离子团簇的能量最低结构相似. 稳定性分析表明Ti_nO₂具有很高的稳定性, 特别是TiO₂和Ti₇O₂. 此外, 详细讨论了团簇的电离势、电子亲和能、电子解离能和能隙. 基于最低能量结构, 讨论了团簇的磁性, 发现电荷从Ti 原子向O原子转移, 并且电荷转移主要发生在Ti_nO₂的Ti-3d、Ti-4s和O-2p轨道. 磁性团簇中反铁磁序占据主导, 磁矩主要来源Ti-3d电子的贡献, 而两个氧原子的贡献非常小.

Structural,Electronic and Magnetic Properties of TinO2 and TinO2- (n=1-10) Clusters

The structural, electronic, and magnetic properties of Ti_nO₂ and Ti_nO₂^- (n=1-10) clusters are studied using density functional theory with the B3LYP hybrid density functional. The calculated geometries show that the two dissociative oxygen atoms remain on the surface of pure Ti_n clusters and do not change the geometry of Ti_n much. The two oxygen atoms exist in the vicinity of Ti_nO₂ clusters, exhibiting an O-Ti-O connection in Ti_nO₂. The geometries of the lowest-energy neutral and anionic clusters are similar. Stability analyses reveal that Ti_nO₂ clusters are highly stable, especially TiO₂ and Ti₇O₂ clusters. In addition, the ionization potentials, electron affinities, electron detachment energies, and energy gaps of the systems are carefully investigated. On the basis of their optimized structures, we discuss the magnetic properties of the two systems. Charge transfer occurs from Ti to O atoms, mainly between Ti-3d, Ti-4s, and O-2p orbitals of Ti_nO₂ clusters. Antiferromagnetic ordering is dominant in the two systems. The magnetic moment of Ti_nO₂ is clearly dominated by the localized 3d electrons of Ti atoms, and the two oxygen atoms contribute a very small amount of spin in Ti_nO₂ clusters.