Multiphonon relaxation of rare-earth ions in oxide glasses

Journal Article · Fri Jul 01 04:00:00 EDT 1977 · Phys. Rev., B; (United States)

DOI:https://doi.org/10.1103/PhysRevB.16.10· OSTI ID:7100555

Layne, C B; Lowdermilk, W H; Weber, M J

Nonradiative decay of excited rare-earth ions by multiphonon emission has been investigated in a series of oxide glasses. Various rare-earth electronic levels were selectively excited by short-duration laser pulses and multiphonon relaxation rates were determined from measurements of fluorescence rise and decay times. Time resolution for fluorescence measurements was 3 nsec, so excited states were probed for which the decay was predominantly nonradiative. Excited states of Nd/sup 3 +/, Er/sup 3 +/, and Tm/sup 3 +/ with energy gaps to the next-lower J state ranging from 1300 to 4700 cm/sup -1/ were studied. The multiphonon relaxation rates for each glass investigated exhibited an approximately exponential dependence on energy gap. Evidence of breakdown of this dependence was observed in the region of small energy gaps. The measured temperature dependences of the decay rates establish that the relaxation occurs predominantly by excitation of the highest-frequency vibrations associated with stretching modes of the glass network former. Borate, silicate, phosphate, germanate, and tellurite glasses were studied. From Raman spectra, the highest-frequency vibrations for these glasses ranged from 700 to 1400 cm/sup -1/. The corresponding multiphonon relaxation rates for a given energy gap differed by three orders of magnitude. The strength of the ion-phonon coupling was found to be approximately equal for all glasses.

• Research Organization: Lawrence Livermore Laboratory, University of California, Livermore, California 94550
• OSTI ID: 7100555
• Journal Information: Phys. Rev., B; (United States), Journal Name: Phys. Rev., B; (United States) Vol. 16:1; ISSN PLRBA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ATOMIC IONS
CHALCOGENIDES
CHARGED PARTICLES
DE-EXCITATION
ELECTRONIC STRUCTURE
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
ERBIUM IONS
EXCITED STATES
FLUORESCENCE
GLASS
IONS
LUMINESCENCE
NEODYMIUM IONS
OPTICAL PUMPING
OXIDES
OXYGEN COMPOUNDS
PHONONS
QUASI PARTICLES
RELAXATION
TEMPERATURE DEPENDENCE
THULIUM IONS