Energy transfer from Gd3+ to Tb3+ in solution

The use of the 4f⁷ ion Gd³⁺ as an energy transfer donor in solution is reported for the first time. The luminescence from the ⁶P multiplet term of Gd³⁺ in chloride solution is quenched not only by increasing concentration, but also by the addition of Tb³⁺. The energy transfer from Gd³⁺ to Tb³⁺ in solution has been followed by selective decay measurements and the energy transfer constant shows a linear relationship with Tb³⁺ concentration up to ∼0.05 M, after which value saturation is reached. The Tb³⁺ acceptor ⁵D₄ emission intensity as a function of time is well-modeled. © 2008 Elsevier B.V. All rights reserved.