Electronic Raman spectra of divalent cobalt ions in cadmium-chloride—type crystals
1975; American Physical Society; Volume: 12; Issue: 11 Linguagem: Inglês
10.1103/physrevb.12.4656
ISSN0556-2805
AutoresJ. C. Christie, I W Johnstone, G. D. Jones, K. Žďánský,
Tópico(s)Chalcogenide Semiconductor Thin Films
ResumoThe polarized Raman spectra of divalent cobalt ions at concentrations ranging from 2.5 to 10 wt% in cadmium chloride, cadmium bromide, manganese chloride, and cobalt chloride from 15 to 300\ifmmode^\circ\else\textdegree\fi{}K are reported. All five electronic transitions between the spin-orbit and trigonal crystal-field-split levels of the $^{4}T_{1g}(^{4}F)$ cubic-field ground term are observed with frequencies of 235, 499, 923, 953, and 1088 ${\mathrm{cm}}^{\ensuremath{-}1}$ for cadmium-chloride crystals containing 2.5-wt% cobalt. The strong-field matrices of the trigonal crystal field and the Zeeman interaction are calculated and quantitatively explain the experimental data. The ${d}^{3}$ configuration parameter values for the cadmium-chloride crystals with 2.5-wt% cobalt are (in ${\mathrm{cm}}^{\ensuremath{-}1}$) $Dq=\ensuremath{-}670$, $B=790$, $C=3320$, $\ensuremath{\zeta}=\ensuremath{-}512$, ${\ensuremath{\zeta}}^{\ensuremath{'}}=\ensuremath{-}513$, $v=57$, and ${v}^{\ensuremath{'}}=\ensuremath{-}345$. EPR measurements on the cadimum-bromide crystals with 0.1-wt% cobalt yield new values of ${g}_{\ensuremath{\parallel}}=3.74\ifmmode\pm\else\textpm\fi{}0.1$ and ${g}_{\ensuremath{\perp}}=4.67\ifmmode\pm\else\textpm\fi{}0.1$ which resolve difficulties in fitting the experimental data for this crystal. Raman lines were also observed for antiferromagnetically ordered Co${\mathrm{Cl}}_{2}$.
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