Spectroscopic properties of neodymium-activated scandium garnets

The Czochralski method was used to synthesize neodymium-activated mixed garnets Gd₃Sc₂Al₃O₁₂ and Gd₃(GaSc)₅O₁₂. An analysis of the optical spectra yielded the crystal splitting schemes of the ⁴F_3/2, ⁴I_9/2, ⁴I_11/2 Nd³⁺. levels of Nd³⁺. The kinetics of decay of the metastable state of Nd³⁺ in these compounds was investigated for various activator concentrations. It was found that, when the Nd³⁺ concentration was 5 wt. % in Gd₃Sc₂Al₃O₁₂ and 2 or 5 wt. % in Gd₃(GaSc)₅O₁₂, this decay was affected considerably by the direct donor-acceptor interaction, which resulted in nonradiative loss of the excitation.