Effects of pressure on the spectra and lifetimes of NdxY1-xP5O14and ruby

Variations in the fluorescence line positions, linewidth, and lifetimes with hydrostatic pressure up to about 80 kbar are reported for samples of NdP 5 O 14 and Nd 0.1 Y 0.9 P 5 O 14 . The results for the lightly doped sample are consistent with changes in the radiative decay rate while the very different results obtained on the heavily doped sample are interpreted in terms of increased radiationless quenching due to energy migration to trapping sites. Results are also reported on the variations in the fluorescence lifetimes of the R lines, and the positions of the N lines and vibronic peaks of ruby as a function of hydrostatic pressure.