Electric dipole polarizabilities of Ni12-58

The electric dipole polarizabilities of Ni-12-Ni-58 have been measured via a molecular beam deflection experiment. The majority of the clusters display polarizabilities alpha between 4 and 6 Angstrom (3) per atom, below the atomic value of 6.8 Angstrom (3) and above that predicted for ideal conducting spheres. Local extrema in alpha /atom are observed for certain Ni-n. In particular, those clusters that adopt closely packed or quasispherical structures (e.g., Ni-38, Ni-55) display local minima, while Ni-21, Ni-22, Ni-25, and Ni49-54, each an icosahedron or polyicosahedron with "missing" atoms, display anomalously high values. The relationship between the polarizabilities of nickel clusters and their shapes and structures is discussed. (C) 2001 American Institute of Physics.