Peculiarities of the Ni2+ ions in the crystal lattice of Bi12SiO20:Ni

Absorption measurements are taken over a wide spectral range which includes the visible, near and far IR region (500-22,272 cm(-1)). The exponential absorption edge parameters sigma(T), sigma(o). W-d and g are calculated for undoped and Ni doped Bi12SiO20 at room temperature. The dopant nickel ion is double-charged and occupies the tetrahedral sites in the crystal lattice of doped sillenite. The energy level structure of the Ni2+ ion in Bi12SiO20:Ni (BSO:Ni) is also presented. The crystal field parameter Dq and the Racah parameters B and C are calculated. It is established that the Jahn-Teller effect displays very strong influence in a distored tetrahedral Ni2+ complex. The two-photon absorption of BSO:Ni is studied in far IR region. (c) 2011 Elsevier B.V. All rights reserved.