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Author Knight, L. B. (Jr.) ♦ Keller, K. A. ♦ Babb, R. M. ♦ Morse, M. D.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword PHYSICS ♦ TITANIUM IONS ♦ PARAMAGNETISM ♦ LASER-RADIATION HEATING ♦ HYPERFINE STRUCTURE ♦ CRYSTAL FIELD ♦ L-S COUPLING ♦ ENERGY-LEVEL TRANSITIONS ♦ ZEEMAN EFFECT ♦ EPR SPECTRA ♦ ENERGY-LEVEL SPLITTING
Abstract Electron-spin resonance studies of laser-ablated titanium metal isolated in neon and argon display an intense feature which exhibits a symmetric, narrow line and a large matrix-dependent {ital g} shift. On the basis of a number of experiments, this is assigned to a matrix isolated 3{ital d}{sup 3},{sup 4}{ital F} Ti{sup +} ion in an octahedral matrix environment. Although the ground state of the gas-phase Ti{sup +} ion is 3{ital d}{sup 2}4{ital s}{sup 1},{sup 4}{ital F}, the assignment to the 3{ital d}{sup 3},{sup 4}{ital F} state is supported by the small hyperfine structure which is observed. The neon magnetic parameters are: {ital g}=1.934(1) and {ital A}({sup 47}Ti)=64(1) MHz; for argon, {ital g}=1.972(1) and {ital A}=56(1) MHz. This unusual stabilization of an excited atomic state by a rare gas matrix is consistent with {ital ab} {ital initio} studies, and has been previously found for atomic nickel. A crystal-field study of the expected behavior of a {ital d}{sup 3},{sup 4}{ital F} ion isolated in a tetrahedral, octahedral, or cuboctahedral environment supports the assignment to an octahedral Ti{sup +}(Rg){sub 6} species, and using the atomic spin{endash}orbit parameter, {zeta} permits accurate values of {ital Dq} to be derived from the measured {ital g} values. Finally, it is also noted that for small values of {ital Dq}/({ital Dq}+{zeta}), or for a {ital d}{sup 3},{sup 4}{ital F} ion in a tetrahedral environment, an as yet unobserved, unequal Zeeman splitting of the fourfold degeneracy occurs, causing a departure of the Zeeman energies from the standard formula of {ital E}{sup Zeeman}={beta}{sub {ital eH}}{sub 0}{ital gM}, with {ital M}={plus_minus}3/2, {plus_minus}1/2. For these situations it becomes necessary to define two values of {ital g}, corresponding to the more strongly ({ital g}{sub 3/2}) and less strongly ({ital g}{sub 1/2}) affected Zeeman levels, respectively. {copyright} {ital 1996 American Institute of Physics.}
ISSN 00219606
Educational Use Research
Learning Resource Type Article
Publisher Date 1996-10-01
Publisher Place United States
Journal Journal of Chemical Physics
Volume Number 105
Issue Number 13


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