A theoretical study on structural and electronic properties of Zr-doped B clusters: ZrBn (n = 1-12)

The geometry, stability, and electronic properties of the ZrBn (n = 1-12) clusters and comparison with pure Bn clusters have been theoretically investigated with the generalized gradient approximation (GGA) based on the density functional theory. It was found that the ground state structures of the Bn clusters are substantially modified by the encapsulation of the Zr atom. Dopant of the Zr atom improves the stability of the host clusters, but reduces the energy gap in most cases. The exceptional case is n = 8, 12 in which the energy gap clearly increases due to the strong elevation of the lowest unoccupied molecular orbital (LUMO). The calculated second-order difference of energies manifests that the magic numbers of stability are 3, 7, 10 for the ZrBn clusters. What is interesting is that the magnetic moment of the B atoms in ZrB3 exhibits the antiferromagnetic alignment in contrast to the ferromagnetic alignment of other sized clusters with odd numbers. Among all of the ZrBn clusters, ZrB7 is the most stable species with a high symmetry (C6v) and relatively large magnetic moment of the Zr atom.