Publications [#233712] of Richard A. Palmer
Journal Articles
- May, PS; Metcalf, DH; Richardson, FS; Carter, RC; Miller, CE; Palmer, RA, ""Measurement and Analysis of Excited State Decay Kinetics and Chiroptical Activity in the 6HJ --4G5/2 Transition of Sm3+ in Trigonal Na3[Sm(CH4O5)", Luminesc., 1992, 51(5), 249, Elsevier BV [Gateway.cgi], [doi].
(last updated on 2024/07/16)Abstract:
Axial total luminescence (TL) and circularly polarized luminescence spectra are presented for the 6HJ (J = 5 2, 7 2, 9 2) ← 4G 5 2 transition regions of Na3[Sm(oxydiacetate)3]·2NaClO4·6H2O (SmODA) for sample temperatures of 77 K and room temperature (∼ 300 K). TL and CPL data are rationalized in terms of dipole strengths and rotatory strengths of transitions between the individual crystal-field levels of Sm3+. The calculation of dipole- and rotatory strengths was accomplished using crystal-field wave functions and electric-dipole intensity parameters determined in previous studies of the polarized absorption spectra of Sm3+ in SmODA. Calculated dipole strengths and rotatory strengths for crystal-field transitions in the 6HJ(J = 5 2, 7 2, 9 2) ← 4G 5 2 regions are given. Simulated TL/CPL spectra are generated from calculated dipole- and rotatory strengths, and are compared to observed data. Excellent agreement is found between theory and observation. Non-radiative deactivation of 4G 5 2 emission in SmODA and 5D0 emission in EuODA is investigated. It is shown that two vibrational modes are active in non-radiative deactivation from these states: the C-H stretching mode of the oxydiacetate ligand; and the O-H stretching mode of lattice waters. Multiphonon emission due to interaction with both vibrational modes is analyzed in terms of the modified energy-gap law of Van Dijk and Schuurmans. It is found that both modes couple with near-equal strengths to the lanthanide ion. It is suggested that the processes promoting the multiphonon transitions may have different efficiencies for the two active vibrational modes in these systems. © 1992.