A pair-potentials analysis of the emission spectroscopy of P13 state atomic mercury isolated in solid Ar, Kr, and Xe

The low-lying electronic states of Yb isolated in a solid Ar matrix grown at 4.2 K are characterized through absorption and emission spectroscopy. Yb atoms are found to occupy three distinct thermally stable trapping sites labeled "red," "blue," and "violet" according to the relative positions of the absorption features they produce. Classical simulations of the site structure and relative stability broadly reproduced the experimentally observed matrix-induced frequency shifts and thus identified the red, blue, and violet sites as due to respective single substitutional (ss), tetravacancy (Tv), and hexavacancy (Hv) occupation. Prolonged excitation of the (1)S → (1)P transition was found to transfer the Yb population from hv sites into Tv and ss sites. The process showed reversibility in that annealing to 24 K predominantly transferred the Tv population back into Hv sites. Population kinetics were used to deduce the effective rate parameters for the site transformation processes. Experimental observations indicate that the blue and violet sites lie close in energy, whereas the red one is much less stable. Classical simulations identify the blue site as the most stable one.

Section: B Model Of Migrationmentioning

confidence: 92%

Heat- and light-induced transformations of Yb trapping sites in an Ar matrix

Tao

Kleshchina

Lambo

et al. 2015

“…The multicomponent nature of the 3 P 1 state emission is shown not to arise from solid state effects such as multiple site trapping. Its origin is examined in the theoretical paper directly following 6 where the energetics of excited state vibronic modes are calculated with pair-potential methods for Hg( 3 P 1 )/RG 18 clusters.…”

Section: Discussionmentioning

confidence: 99%

“…The origin of the multiple emission components in the Hg/RG systems is known from excitation scans not to be due to multiple site occupancy. Pairpotential simulations described in the following paper, 6 present a model which explains the origin of multiple emission features for atomic mercury isolated at a single site. These calculations also suggest a mechanism for the quenching of the central emission component in the 273 nm emission in the Hg/Xe system.…”

Section: Discussionmentioning

confidence: 99%

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Luminescence spectroscopy of P13 and P3 state atomic mercury isolated in solid Ar, Kr, and Xe

Collier¹,

McCaffrey²

2003

Self Cite

Multicomponent emission bands are recorded for the 3 P 1 → 1 S 0 transition of atomic mercury isolated at single sites in solid Ar, Kr, and Xe matrices. A blueshift observed at elevated temperatures on the 273 nm emission of Hg/Xe is identified in line shape analysis as arising from decreasing intensity of the central component in the band profile. The origin of the multiple components in the emission bands is ascribed to the existence of several vibronic modes which lead to excited state stabilization in the Hg( 3 P 1 )/RG matrix systems. A detailed description of these modes and their energetics is presented in the paper directly following. Photoexcitation of the 3 P 1 state also yields small amounts of 3 P 0 state emission. Hg atom 3 P 1 to 3 P 0 state intramultiplet relaxation ͑IMR͒ is most efficient in Hg/Xe where the ratio of this relaxation channel to 3 P 1 state radiative decay is 1/200 as established in time-integrated emission spectra. Despite the weakness of IMR, pulsed laser excitation combined with photon counting detection provide time-gated 3 P 0 state emission spectra largely free of the more intense 3 P 1 state emission. Such emission spectra recorded under high resolution for the 3 P 0 → 1 S 0 transition of atomic mercury isolated in solid Xe provide the first example of the occurrence of a zero-phonon lines for a metal atom isolated in a rare gas matrix. Wp line shape analysis conducted on the emission bands recorded at specific temperatures, confirm this assignment. The electron-phonon coupling strength ͑Huang-Rhys, S factor͒ extracted in the line shape fits for the Hg/Xe transition is 1.3. Slightly stronger coupling is identified in Kr (S ϭ2.2) and stronger still in Ar (Sϭ3.3). Analysis of the diatomic Hg•RG potential energy curves reveal that the origin of the weak electron-phonon coupling lies primarily in the similarity in the ground and excited states, but also indicates the site size offered by the host solid plays a role.

“…The preference for a single site in solid Xe, and the correlation of the matrix-shifts observed for the blue sites, allows the assignment of the blue sites to the trapping of Mn atoms in single substitutional sites of these matrices. Our previous simulation work on the matrix-isolated Group 12 metal atoms Zn, 5 Cd, 28 and Hg, 29 indicated single substitutional site occupancies for these M•RG diatomics that have comparatively short bond lengths. The present predictions for the site occupancies in the Mn/RG matrix systems are consistent with the earlier simulations because of the longer ground state bond length expected in manganese-rare gas diatomics.…”

Section: B Site Occupancymentioning

confidence: 99%

The absorption and excitation spectroscopy of matrix-isolated atomic manganese: Sites of isolation in the solid rare gases

Collier

McCaffrey

2005

Self Cite

This study collects information from absorption and luminescence excitation spectra recorded for Mn atoms isolated in the solid rare gases Ar, Kr, and Xe and presents an analysis of the site occupancy, based on the polarizabilities of the rare gases and the observed spectral shifts. Two thermally stable sites of isolation exist for atomic Mn in solid Ar and Kr, while a single thermally stable site is present in Mn/Xe. Site occupancy assignments are based on the application of a polarizability model to the z 6 P 5/2 ←a 6 S 5/2 ; z 8 P 5/2 ←a 6 S 5/2 , and y 6 P 5/2 ←a 6 S 5/2 electronic transitions of atomic Mn. From an analysis of the observed RG matrix-to-gas phase energy shifts for P←S type transitions, this model allows the association of certain site types occupied by metal atoms in the rare gas solids. The required condition being a linear dependence of the matrix shifts with rare gas polarizability for those metal atoms ''trapped'' in a particular site type. Application of the polarizability model in conjunction with trends observed in site dominance, established a connection between the blue sites in Ar and Kr and the single site in Xe. Use of the known Mg•RG ground state bond lengths facilitated an identification of the sites of Mn atom isolation assuming the transference of the known Mg•RG bond lengths to the Mn•RG systems. Substitutional site occupancy of atomic Mn is assigned to the blue sites in Ar and Kr and the single site in Xe, while tetra-vacancy site occupancy is assigned to the red sites in Ar and Kr. Consistent with these assignments, Mn atoms in solid Ar show a preference for trapping in tetra-vacancy sites whereas in solid Kr, single substitutional sites are preferred and in Xe, this is the only site observed.