Absorption spectral studies of rare earth ions (Pr 3+, Nd 3+, Sm 3+, Dy 3+, Ho 3+ and Er 3+) doped in NASICON type phosphate glass, Na 4AlZnP 3O 12

Abstract

The absorption spectral studies have been performed for rare earth (Pr 3+, Nd 3+, Sm 3+, Dy 3+, Ho 3+ and Er 3+) doped NASICON type phosphate glass, Na 4AlZnP 3O 12 (NAZP) to derive the phenomenological Judd–Ofelt parameters Ω λ ( λ=2, 4, 6). The variation of Ω 2 values with f electrons shows a pronounced rise in the middle of the series arises due to the differences in the distribution of sites occupied by the rare earth ions in the present phosphate glass. The hypersensitive nature of absorption transitions of Nd 3+, Er 3+ and Ho 3+ are explained in the light of covalency and site asymmetry effects. Emission studies of Eu 3+ and Dy 3+ indicate that these rare earths are situated in highly distorted sites compared to other fluoride, phosphate and oxyfluoride glasses.