Absorption spectral studies of rare earth ions (Pr3+, Nd3+, Sm3+, Dy3+, Ho3+ and Er3+) doped in NASICON type phosphate glass, Na4AlZnP3O12

The absorption spectral studies have been performed for rare earth (Pr3+, N d3+, Sm3+: Dy3+, Ho3+ and Er3+) doped NASICON type phosphate glass, Na4AlZn P3O12 (NAZP) to derive the phenomenological Judd-Ofelt parameters Omega(lam bda) (lambda = 2, 4, 6). The variation of Omega(2) values with f electrons shows a pronounced rise in the middle of the series arises due to the diffe rences in the distribution of sires occupied by the rare earth ions in the present phosphate glass. The hypersensitive nature of absorption transition s of Nd3+, Er3+ and Ho3+ are explained in the light of covalency and site a symmetry effects. Emission studies of Eu3+ and Dy3+ indicate that these rar e earths are situated in highly distorted sites compared to other fluoride, phosphate and oxyfluoride glasses. (C) 2000 Elsevier Science B.V. All righ ts reserved.