Scintillation mechanisms in rare earth orthophosphates

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:192451

Wojtowicz, A J; Wisniewski, D ^[1]; Lempicki, A ^[2]

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1. N. Copernicus Univ., Torun (Poland). Institute of Physics
2. Boston Univ., MA (United States). Chemistry Dept.; and others

In this Communication we present results of our studies on scintillation properties of rare earth orthophosphates. Despite of the PO{sub 4} group high frequency vibrations, which limit the conversion efficiency in orthophosphate lattices, some of them are very promising, as evidenced by the exceptionally good scintillation properties of LuPO{sub 4}:Ce. We have studied the following orthophosphate crystals: YbPO{sub 4}:Ce, YbPO{sub 4}, and Lu{sub x}Yb{sup 1-x}PO{sub 4}:Ce. Both Ce and Yb ions scintillate (through d-f transition and charge transfer state decay, respectively) but, unfortunately, they also show strong tendency toward mutual quenching. We propose that nonradiative Yb-Ce energy transfer and the nonradiative decay of the (Yb{sup 2+} + Ce{sup 4+}) charge transfer state are responsible for the observed effect. Therefore ytterbium does not provide cheaper substitute for the optically inactive RE ion (lutetium) in the orthophosphate lattice, on the contrary, it has to be carefully avoided whenever a Ce-activation is used.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States); Uniwersytet Mikolaja Kopernika, Torun (Poland)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 192451
• Report Number(s): CONF-940785--2; ON: DE96004560
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
CERIUM
CRYSTALS
EMISSION SPECTRA
ENERGY TRANSFER
EXCITED STATES
IONS
LUMINESCENCE
LUTETIUM PHOSPHATES
PHOSPHORS
PHOTONS
YTTERBIUM PHOSPHATES