On the luminescence of Bi3+ in the pyrochlore Y2Sn2O7

The photoluminescence and the excitation spectra of Bi3+ in the pyrochlore Y2Sn2O7 have been investigated in the temperature range of 15–300 K. The photoluminescence spectrum of Bi3+ in Y2Sn2O7 consists of two bands, one in the ultraviolet (385 nm) and the other in the visible (515 nm) part of the spectrum. The ultraviolet emission is attributed to the 3P0,1→1S0 transition of isolated Bi3+ ions and the visible luminescence to Bi3+ pairs (clusters) in the host lattice. A comparative study of the Bi3+ luminescence in the pyrochlores Y2Sn2O7, La2Zr2O7 and Gd2GaSbO7 is presented.