The Gd3+ ion has been used to induce quantum splitting in luminescent
materials by using cross-relaxation energy transfer (CRET). In Nd:LiGdF4, quantum
splitting results from a two-step CRET between Gd3+ and Nd3+, first involving a
transition 6G→6I on Gd3+ and an excitation within the 4f3 configuration of Nd3+
followed by...