Raman Spectra of YPO_4 and YbPO_4*

The Raman spectra of crystalline YPO4 and YbPO4 have been excited with a helium–neon 25-mW gas laser operating at 6328 Å. Crystallographic data indicate that PO4 complexes exist in these two isomorphic crystals. This has been confirmed by the present Raman data. Vibrational levels that can be attributed entirely to internal PO43− vibrations were observed. For YPO4 they are 1056, 1023, 997, 578, 481, 330, and 292 cm−1. For YbPO4 they are 1067, 1029, 1007, 580, 481, 325, and 310 cm−1.