Figure 2
TQ properties of M 1.95 Eu 0.05 Si 5- x Al x N 8- x O x materials (M = Ca, Sr, Ba). (a) Temperature-dependent normalized-intensity curves are shown as functions of I T /I 0 = [1 + D exp(−E a/kT)]−1 where I 0 (the intensity at T = 0), D, and E a (the activation energy) are refined variables. (b) The relations of the activation energies and components for different alkaline earth metal series. (Reprinted with permission from reference [18]. Copyright 2012, American Chemical Society).