Influence of the crystal structure on the stability of Ln2+Ln2+ in strontium borates

The results of luminescence measurements on Ln (Eu, Yb) doped alkaline earth (M=Ca,Sr)(M=Ca,Sr) borates M3(BO3)2M3(BO3)2, MB2O4MB2O4, M2B5O9XM2B5O9X(X=Cl,Br)(X=Cl,Br), MB6O10MB6O10, MB4O7MB4O7 after high-temperature annealing in various atmospheres are reported and discussed. The stability of Ln2+Ln2+(Ln=Eu,Yb)(Ln=Eu,Yb) is found to increase in the sequence Sr3(BO3)2