Structure and Stability of Al-Doped Boron Clusters by the Density-Functional Theory

Abstract

The geometries, stabilities, and electronic properties of Bn and AlBn clusters, up to n=12, have been systematically investigated by using the density-functional approach. The results of Bn clusters are in good agreement with previous conclusions. When the Al atom is doped in Bn clusters, the lowest-energy structures of the AlBn clusters favor two-dimensional and can be obtained by adding one Al atom on the peripheral site of the stable Bn when n<or=5. Starting from n=6, the lowest-energy structures of AlBn clusters favor three-dimensional and can be described as an Al atom being capped on the Bn clusters. The average atomic binding energies, fragmentation energies, and second-order energy differences are calculated and discussed. Maximum peaks were observed for clusters of sizes n=5, 8, 11, especially for the AlB8 cluster, implying that these clusters possess relatively higher stability. The adiabatic IP and EA of AlBn and Bn clusters are discussed and compared with some available experimental results. A distinct phenomena for AlBn clusters is that all even n, but n=10, have higher adiabatic ionization potentials than odd n.

Electronic Structures and Thermochemical Properties of the Small Silicon‐Doped Boron Clusters BnSi (n=1–7) and Their Anions

“…[14] On the other hand, extensive experimental and theoretical studies on carbon-boron mixed clusters have been carried out [15][16][17] since a prediction on the existence of planar hexa-coordinated carbon in B 6 C 2À clusters. [15] Boron-silicon compounds have attracted considerable interest due to their potentially important applications in the fields of semiconductor materials and thermoelectric devices.…”

“…A study of phase diagrams of the boron-silicon binary systems indicated the existence of two kinds of B n Si compounds in the boron-rich region (n = 16-26 and also B 6 Si). [18] The B 14 Si cluster was synthesized for the first time by Giese et al, [19] and Imai et al presented X-ray images and studies of the electronic properties of singlet crystal B 18 Si. [20] However, in spite of the demonstrated importance of the boron-silicon compounds, the understanding of the electronic and thermodynamic properties of these materials is still very limited.…”

Theoretical study of geometry, stability and properties of Al and AlSi nanoclusters

“…Figure 2d shows variation of average Al-Al distance of the most stable clusters as a function of cluster size. As can be seen in this figure the average Al-Al distance gradually increases with cluster size while having local oscillation at Al 5 , Al 8 and Al 12 and finally approaches the bulk limit of 2.86 Å [2]. It seems that, unlike binding energy per atom, the average Al-Al distance of the most stable Al n clusters approaches the bulk value rather rapidly with cluster size.…”

“…G* level of theory energy (E f ) which were calculated according to the Eqs. 2 and 3, respectively [8].…”

“…In addition, there is no experimental technique that can provide direct information on cluster geometry [2]. From theoretical aspect, on the other hand, geometry and many other properties of clusters have been successfully predicted and there are abundant reports in the literature that investigate the properties of clusters theoretically [7][8][9][10][11].…”