Excited-state dynamics and energy transfer of +4 curium in cerium tetrafluoride

Journal Article · Sun Apr 01 04:00:00 EDT 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.41.6201· OSTI ID:6948383

Liu, G K; Beitz, J V ^[1]

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1. Argonne National Laboratory, Argonne, Illinois 60439 (USA)

Energy-transfer dynamics of 5{ital f} states of +4 curium in cerium tetrafluoride have been investigated for the first time. Emission from the lowest energy component of the second {ital J}=1 multiplet was studied using time- and frequency-resolved laser-induced fluorescence. The observed dynamics were complex due, in part, to the strong ion-lattice coupling and the dense {ital f}-state energy-level structure of Cm{sup 4+}. The influence of experimental parameters such as excitation frequency, excitation intensity, sample temperature, and prior optical irradiation on the observed nonexponential fluorescence decays was determined. The observed 5{ital f}-state dynamics of 0.1 at. % Cm{sup 4+}:CeF{sub 4} are well fit by a cross-relaxation model, except at low temperature and high excitation intensity, where photoinduced site distortion and ground-state depletion via a two-photon process occurred. In this case, the initial fluorescence decay rate of Cm{sup 4+} on one of the two metal-ion sites was reduced in comparison with the rate observed at lower excitation intensity. A cross-relaxation model incorporating exciton-exciton annihilation was necessary to describe the fluorescence dynamics of 5 at. % Cm{sup 4+}:CeF{sub 4}. The derived energy-transfer rates for 5{ital f} states of Cm{sup 4+} via cross relaxation and up conversion are two orders of magnitude higher, at equal ion densities, than those of lanthanide-ion 4{ital f} states and approach those of transition-metal-ion {ital d} states.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6948383
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 41:10; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ANNIHILATION
BASIC INTERACTIONS
CERIUM COMPOUNDS
CERIUM FLUORIDES
ELECTROMAGNETIC INTERACTIONS
ELECTROMAGNETIC RADIATION
ELECTRONIC STRUCTURE
ENERGY LEVELS
ENERGY TRANSFER
EXCITED STATES
EXCITONS
F STATES
FLUORESCENCE
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
INTERACTIONS
LASER RADIATION
LUMINESCENCE
MATHEMATICAL MODELS
QUASI PARTICLES
RADIATIONS
RARE EARTH COMPOUNDS
RESOLUTION
TIME RESOLUTION
TIMING PROPERTIES