Influence of Temperature on the Luminescence Properties of MgAl2O4:Dy3+ Ceramics Synthesized by Spark Plasma Sintering

Resumo

Transparent MgAl₂O₄:Dy³⁺ ceramic samples were synthesized by spark plasma sintering. Their optical properties, photo- and cathodoluminescence, the luminescence decay kinetics, and the effect of temperature on spectral and kinetic characteristics of luminescence were studied. The luminescence of Dy³⁺ ions (458 nm (⁴I_15/2 → ⁵H_15/2), 480 nm (⁴F_9/2 → ⁶H_15/2), 573 nm (⁴F_9/2 → ⁶H_13/2), 665 nm (⁴F_9/2 → ⁶H_11/2), and 750 nm (⁴F_9/2 → ⁶H_9/2)), impurity Cr³⁺ ions (²E_g → ⁴A_2g), and intrinsic defects (F⁺-centers, 460 nm) was detected. Thermal quenching of luminescence in the visible spectral range was observed as the temperature varied from 100 to 300 K. It is demonstrated that the patterns of quenching for impurity and intrinsic centers differ in MgAl₂O₄:Dy³⁺ ceramics. The mechanisms of thermal quenching are discussed.