Samarium‐Doped Fluorochlorozirconate Glass–Ceramics as Red‐Emitting X‐Ray Phosphors

We have examined the photoluminescence (PL) and X-ray luminescence (XL) of fluorochlorozirconate (FCZ) glass-ceramics (FCZ-GC) doped with Sm 3+ and Sm 2+ ions. Sm-doped FCZ-GCs have been prepared by annealing a ZBLAN glass of nominal composition 53% ZrF 4 , 20% NaF, 3% AlF 3 , 3% LaF 3 , 1% SmF 3 , 1% BaF 2 , 19% BaCl 2 (mol%) above the glass transition of the host glass matrix. SmF 3 was added to the initial glass mix for trivalent samarium doping. Sm 2+ doping was achieved by reducing Sm 3+ to Sm 2+ during the melting of the initial mix by the addition of NaBH 4 . FCZ-GC contains BaCl 2 nanocrystals formed during the annealing with embedded Sm 2+ ions, which dominate PL and XL. The PL of Sm 2+ ions embedded in BaCl 2 nanocrystals strongly depends on their crystal structure (hexagonal or orthorhombic) and may be used to identify that structure. The correlation of the PL spectra with X-ray diffraction data is used to estimate the size of nanocrystals. The nanocrystals with average dimensions <∼ 30 nm are mainly hexagonal while larger crystals are mostly orthorhombic. XL is more efficient in glass-ceramics containing relatively large BaCl 2 nanocrystals with hexagonal crystal structure.

[1]  S. Kasap,et al.  Optical properties of divalent samarium-doped fluorochlorozirconate glasses and glass ceramics , 2009 .

[2]  S. Schweizer,et al.  Sm-activated barium halide nanocrystals in fluorozirconate glasses , 2008 .

[3]  Jacqueline A. Johnson,et al.  A Glass‐Ceramic Plate for Mammography , 2007 .

[4]  D. Jiang,et al.  Wiggler‐base Hard X‐ray Spectroscopy Beamline at CLS , 2007 .

[5]  Douglas R. MacFarlane,et al.  Eu-activated fluorochlorozirconate glass-ceramic scintillators , 2006 .

[6]  D. Braithwaite,et al.  Structural and electronic transitions in the low-temperature, high-pressure phase of SmS , 2005 .

[7]  P. Dorenbos.  Energy of the first 4f7→4f65d transition of Eu2+ in inorganic compounds , 2003 .

[8]  Grant V. M. Williams,et al.  Photostimulated luminescence in Eu-doped fluorochlorozirconate glass ceramics , 2003 .

[9]  P. Dorenbos.  Crystal field splitting of lanthanide 4fn−15d-levels in inorganic compounds , 2002 .

[10]  Xurong Xu,et al.  Dynamic studies on the time-resolved fluorescence of Sm2+ in BaCl2 , 2002 .

[11]  C. Wickleder.  Excited states of Sm2+ in chloride host lattices , 2001 .

[12]  Grant V. M. Williams,et al.  Structural phase changes in barium bromide nano-crystals in a fluorobromozirconate glass-ceramic x-ray storage phosphor , 2001 .

[13]  N. Umesaki,et al.  X-ray induced reduction of rare earth ion doped in Na2O-Al2O3-B2O3 glasses. , 2001, Journal of Synchrotron Radiation.

[14]  P. Dorenbos.  The 4fn↔4fn − 15d transitions of the trivalent lanthanides in halogenides and chalcogenides , 2000 .

[15]  Heinz von Seggern,et al.  Photostimulable x-ray storage phosphors: a review of present understanding , 1999 .

[16]  Douglas R. MacFarlane,et al.  In situ generation of Eu2+ in glass-forming melts , 1999 .

[17]  Yongrong Shen,et al.  EFFECT OF PRESSURE AND TEMPERATURE ON 4F-4F LUMINESCENCE PROPERTIES OF SM2+ IONS IN MFCL CRYSTALS (M=BA, SR, AND CA) , 1998 .

[18]  K. Hirao,et al.  X-ray absorption fine structure of samarium-doped borate glasses , 1997 .

[19]  Ishwar D. Aggarwal,et al.  Fluoride Glass Fiber Optics , 1991 .

[20]  H. Eick,et al.  Solvolytic decomposition studies on mixed phases: Synthesis of the anti-Fe2P-type BaX2 (X Cl, Br) from BaX2LnX3 phases☆ , 1989 .

[21]  J. Wilkins,et al.  Relativistic calculations of 3 d excitation energies in the rare-earth metals , 1979 .

[22]  J. Gǎcon,et al.  Some aspects of the Sm2+ centre relaxation in BaClF , 1979 .

[23]  F. K. Fong,et al.  Role of the 4f55d band in the radiationless 5D1→5D0 coupling in BaCl2:Sm2+ and BaBr2:Sm2+ , 1976 .

[24]  L. Alexander,et al.  X-ray diffraction procedures , 1954 .