The energy transfer processes in LaMgB5O10:Pr3+, Mn2+

Pr3+, Mn2+ singly doped and co-doped LaMgB5O10 samples were prepared by solid-state reaction and their spectroscopic properties were investigated by synchrotron radiation VUV light. Significant spectra overlap between the Mn2+6A1g→(4Eg, 4A1g) excitation (centered at 412 nm) and the Pr3+1S0→(1I6, 3PJ) emission (410 nm) provided the possibility of energy transfer from Pr3+ to Mn2+. In the LaMgB5O10:Pr3+, Mn2+ samples investigated, the expected energy transfer process was observed as comparing the emission spectra of LaMgB5O10:Pr3+, Mn2+ samples with that of the LaMgB5O10:Mn2+. The shorter decay time of the 1S0→(1I6, 3PJ) transition in the co-doped samples was also an evidence of energy transfer from Pr3+ to Mn2+. By analyzing the energy transfer process, it was found that the energy transfer process in LaMgB5O10:Pr3+, Mn2+ was likely of resonant energy transfer and the re-absorption process can be excluded. The critical distances of energy transfer based on the electric dipole-dipole interaction and electric dipole-quadrupole interaction were calculated to be 4.78 and 9.46 Å in LaMgB5O10:Pr3+, Mn2+, respectively, which are smaller than the mean distance of Pr3+ and Mn2+ (17 Å) in the highest concentration-doped sample. The near neighboring PrMn clusters formed in the LaMgB5O10 host is responsible for the energy transfer process.