Influence of temperature on the luminescence properties of MgAl$_{2}$O$_{4}$ : Dy ceramics synthesized by spark plasma sintering

Transparent MgAl$_{2}$O$_{4}$ : Dy 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 Dy$^{3+}$ 458 (${}^{4}I_{15/2}\to{}^{5}H_{15/2}$), 480 nm (${}^{4}F_{9/2}\to{}^{6}H_{15/2}$), 573 nm (${}^{4}F_{9/2}\to{}^{6}H_{13/2}$), 665 nm (${}^{4}F_{9/2}\to{}^{6}H_{11/2}$), and 750 nm (${}^{4}F_{9/2}\to{}^{6}H_{9/2}$), impurity Cr$^{3+}$ ions (${}^{2}E_{g}\to{}^{4}A_{2g}$), 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 MgAl$_{2}$O$_{4}$ : Dy ceramics. The mechanisms of thermal quenching are discussed.