“…5(b), the emission intensity of the LLS:0.3%Mn 4+ ,1.6%Mg 2+ phosphors at 423 K remained about 58% compared that at 303 K, which was better than that of Ca 3 La 2 W 2 O 12 :Mn 4+ (29%), CaLaMgNbO 6 :Mn 4+ (45%), SrLaScO 4 :Mn 4+ (15%), and Gd 2 -ZnTiO 6 :Mn 4+ (27.2%), [61][62][63][64] indicating that the LLS:0.3% Mn 4+ ,1.6%Mg 2+ phosphors had good thermal stability. The corresponding activation energy can be obtained by using the following expression: 65,66 IðTÞ…”