IRRS, UV-Vis-NIR absorption and photoluminescence upconversion in Ho{sup 3+}-doped oxyfluorophosphate glasses

Journal Article · Thu Sep 15 00:00:00 EDT 2005 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2005.06.007· OSTI ID:20729071

Karmakar, Basudeb ^[1]

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1. Glass Division, Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata 700 032 (India)

Infrared reflection spectroscopic (IRRS), ultraviolet-visible-near infrared (UV-Vis-NIR) absorption and photoluminescence upconversion properties with special emphasis on the spectrochemistry of the oxyfluorophosphate (oxide incorporated fluorophosphates) glasses of the Ba(PO{sub 3}){sub 2}-AlF{sub 3}-CaF{sub 2}-SrF{sub 2}-MgF{sub 2}-Ho{sub 2}O{sub 3} system have been studied with different concentrations (0.1, 0.3 and 1.0 mol%) of Ho{sub 2}O{sub 3}. IRRS spectral band position and intensity of Ho{sup 3+} ion doped oxyfluorophosphate glasses have been discussed in terms of reduced mass and force constant. UV-Vis-NIR absorption band position has been justified with quantitative calculation of nephelauxetic parameter and covalent bonding characteristics of the host. NIR to visible upconversion has been investigated by exciting at 892 nm at room temperature. Three upconverted bands originated from the {sup 5}F{sub 3}{yields}{sup 5}I{sub 8} ({sup 5}S{sub 2}, {sup 5}F{sub 4}){yields}{sup 5}I{sub 8} and {sup 5}F{sub 5}{yields}{sup 5}I{sub 8} transitions have found to be centered at 491 nm (blue, medium), 543 nm (green, very strong) and 658 nm (red, weak), respectively. These bands have been justified from the evaluation of the absorption, normal (down conversion) fluorescence and excitation spectra. The upconversion processes have been explained by the excited state absorption (ESA), energy transfer (ET) and cross relaxation (CR) mechanisms involving population of the metastable (storage) energy levels by multiphonon deexcitation effect. It is evident from the IRRS study that the upconversion phenomena are expedited by the low multiphonon relaxation rate in oxyfluorophosphate glasses owing to their high intense low phonon energy ({approx}600 cm{sup -1}) which is very close to that of fluoride glasses (500-600 cm{sup -1})

• OSTI ID: 20729071
• Journal Information: Journal of Solid State Chemistry, Vol. 178, Issue 9; Other Information: DOI: 10.1016/j.jssc.2005.06.007; PII: S0022-4596(05)00275-6; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ABSORPTION
ALUMINIUM FLUORIDES
CALCIUM FLUORIDES
COVALENCE
DOPED MATERIALS
ENERGY TRANSFER
EXCITED STATES
FLUORESCENCE
GLASS
HOLMIUM IONS
HOLMIUM OXIDES
MAGNESIUM FLUORIDES
PHOTOLUMINESCENCE
RELAXATION
SPECTRA
STRONTIUM FLUORIDES
TEMPERATURE RANGE 0273-0400 K
ULTRAVIOLET RADIATION