Ferroelectric Properties and Spectroscopic Characterization of Pb(Mg_1/3Nb_2/3)O₃-32PbTiO₃:Er³⁺/Sc³⁺ Crystal

An Er3+/Sc3+ co-doped 0.68Pb(Mg1/3Nb2/3)O3-0.32PbTiO3 ferroelectric single crystal was grown by high-temperature flux method. The remnant polarization Pr is 27.97 µC/cm2 and the coercive field Ec is 8.26 kV/cm for [100] oriented crystal. Green (524 and 551 nm) and red (654 nm) emission bands are generated at the 980 nm excitation, which corresponds to the 2H11/2→ 4I15/2, 4S3/2→ 4I15/2 and 4F9/2→ 4I15/2 transitions of Er3+, respectively. Judd–Ofelt theory has been applied to predict the spectroscopic characteristics of the as-grown crystals. The obtained J–O intensity parameters Ωt (t = 2, 4 and 6) are Ω2 = 0.76 × 10−20 cm2, Ω4 = 1.0 × 10−20 cm2, Ω6 = 0.55 × 10−20 cm2. Spectroscopic characteristics, including optical transition probabilities, branching ratio, and radiative lifetime of Er3+ in the crystal, are determined. The calculated radiative lifetimes of 4I13/2 and 4I11/2 energy levels are 2.82 ms and 2.61 ms, respectively. These investigations provide possibilities for the crystal Pb(Mg1/3Nb2/3)O3-0.32PbTiO3:Er3+/Sc3+ to be a new type of multifunctional crystal integrating electricity-luminescence.