title: Photoluminescence and Raman studies of Sm3+ and Nd3+ ions in zirconia matrices: example of energy transfer and host-guest interactions.
abstract: Photoluminescence and Raman studies on Sm(3+)- and Nd(3+)-doped zirconia are reported. The Raman studies indicate that the monoclinic (m) phase dominates up to a 10 at.% lanthanide level, while stabilization of the cubic phase is attained at approximately 20 and approximately 25 at.% of Sm(3+) and Nd(3+), respectively. Both systems are strongly luminescent under photo-excitation. The emission spectrum at 77 K of the ZrO(2):Sm(3+) system consists of a broad band at 505 nm, that corresponds to the zirconia matrix. At room temperature the band maximum blue-shifts to 490 nm. Sharper bands corresponding to f-f transitions within the Sm(3+)ion are also exhibited in the longer wavelength region of the spectrum. Exclusive excitation of the zirconia matrix provides sensitized emission from the acceptor Sm(3+) ion. The excitation profile is dominated by a broad band at 325 nm when monitored either at the zirconia or at one of the Sm(3+) emissions. A spectral overlap between the 6H(5/2)-->(4)G(7/2) absorption of the Sm(3+) ion with the zirconia emission leads to an efficient energy transfer process in the systems. Multiple facets of the spectral behavior of the Sm(3+) or Nd(3+) in the zirconia matrices, as well as the effects of compositions on the emission and Raman properties of the materials, and the role of defect centers in photoluminescence and the energy transfer processes are discussed.
authors.affiliation: Oak Ridge National Laboratory, Chemical Sciences Division, MS 6375, Oak Ridge, TN 37831-6375, USA. assefaz@ornl.gov
authors.forename: Zerihun
authors.initials: Z
authors.lastname: Assefa
authors.forename: R G
authors.initials: RG
authors.lastname: Haire
authors.forename: P E
authors.initials: PE
authors.lastname: Raison
mesh_terms: D004735:Energy Transfer; D007477:Ions; D008027:Light; D049449:Luminescence; D009354:Neodymium / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D012493:Samarium / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013696:Temperature; D015040:Zirconium / Q000737:chemistry*
chemical_list: D007477:Ions; D009354:Neodymium; D012493:Samarium; D015040:Zirconium; D009584:Nitrogen