An alternative interpretation of the optical spectra for Fe3+-doped KTaO3 crystals

In this paper, the excitation spectrum and luminescence at 14 569, 17 225, 18 829 and 14 659 cm(-1) for Fe3+ ion at the K+ site of KTaO3 crystals are assigned, respectively, to the (6)A(1) (S) -> T-4(1)(G), T-4(2)(G), E-4(1)(G)[(4)A(1)(G)] and T-4(1)(G) -> (6)A(1)(S) transitions rather than to the (6)A(1) (S) -> T-4(1) (G), T-2(2)(G), T-4(2)(G) and T-4(1)(G) -> (6)A(1)(S) transitions given in a previous paper [Bryknar et al., Radiat. Eff. Def. Solids 149(1999)51]. On the basis of this assignment, the reasonable optical spectrum parameters (in particular, the cubic field parameter Dq approximate to -640 cm(-1)) are obtained. The validity of this assignment is discussed. (C) 2006 Elsevier B.V. All rights reserved.