The energy transfer processes in LaMgB 5O 10:Pr 3+, Mn 2+

Abstract

Pr 3+, Mn 2+ singly doped and co-doped LaMgB 5O 10 samples were prepared by solid-state reaction and their spectroscopic properties were investigated by synchrotron radiation VUV light. Significant spectra overlap between the Mn 2+ 6A 1g→( 4E g, 4A 1g) excitation (centered at 412 nm) and the Pr 3+ 1S 0→( 1I 6, 3P J) emission (410 nm) provided the possibility of energy transfer from Pr 3+ to Mn 2+. In the LaMgB 5O 10:Pr 3+, Mn 2+ samples investigated, the expected energy transfer process was observed as comparing the emission spectra of LaMgB 5O 10:Pr 3+, Mn 2+ samples with that of the LaMgB 5O 10:Mn 2+. The shorter decay time of the 1S 0→( 1I 6, 3P J) transition in the co-doped samples was also an evidence of energy transfer from Pr 3+ to Mn 2+. By analyzing the energy transfer process, it was found that the energy transfer process in LaMgB 5O 10:Pr 3+, Mn 2+ 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 LaMgB 5O 10:Pr 3+, Mn 2+, respectively, which are smaller than the mean distance of Pr 3+ and Mn 2+ (17 Å) in the highest concentration-doped sample. The near neighboring Pr Mn clusters formed in the LaMgB 5O 10 host is responsible for the energy transfer process.