OPTICAL STUDY OF PRASEODYMIUM-3-TYPE ORTHOVANADATE PHASES( IN ZIRCON)

Investigation of the optical spectra of Pr3+ (4f(2) configuration) emb edded in the zircon-type rare earth orthovanadates REVO4, RE = Pr, Gd, Y and Sc, using the fluorescence, visible and near infrared absorptio n spectroscopies have been done. Energy level schemes are deduced from the optical data. Only three from seven expected sublevels for H-3(4) ground manifold were observed. Their positions are situated at 0-34-8 1, 0-53-82, 0-59-83 and 0-(85)-85 cm(-1) in PrVO4, (Pr0.1Gd0.9)VO4, (P r0.1Y0.9)VO4 and (Pr0.1Sc0.9)VO4, respectively. For ScVO4 matrix rathe r poor information is obtained, but the levels observed follow the lin ear and smooth evolution across the rare earth series. This comportmen t confirms the isostructural character of the rare earth environment, yttrium and scandium included, in the studied compounds. According to this assertion some non-observed electronic transitions are deducted f rom curves, e.g. H-3(4) (B-2) --> P-3(1) (A(2)) transition. (C) 1998 E lsevier Science B.V. All rights reserved.