Knowledge Bank

“The absorption spectrum of $KNiF3$ and that of Ni in $KMgF3$ will be reported. The spectra have been analyzed and the following results and interpretations obtained: (a) The oscillator strengths for the transitions from the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}A2g$ ground state to the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}T2g,\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}T1ga,\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}E1,\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}T2g$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">8</mrow>}T1gb$ states are $6.3\times 10-6,7.8\times 10-6,1.1\times 10-6,1.9\times 10-6$ and $2.1\times 10-5$, respectively, at $20^{\circ} $K. (b) The transition $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}A2g\leftrightarrow \mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}2g$ (theoretical oscillator strength $6\times 10$-6) is predominantly magnetic dipole in nature, the others are electric $dipole.1$ (c) A value for the spin-orbit coupling constant $\lambda$, between 305 and $317cm-1$, has been found from the spin-orbit splitting of the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}T2g$ state. The spin-orbit splittings of the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}T1ga$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}T1gb$ states can be interprets -with this value of $\lambda$. (d) An analysis of the vibrational structure of the electronic transitions has been made. (e) The observed energy levels can be accurately fitted using a $theory2$ requiring the parameter $F2,F4,\lambda$, and Dq. The values of $F2,F4$ and $\lambda$ are slightly reduced from the free ion values and the procedure for determining the parameters both in the crystal and for the free ion will be discussed. The results of the analysis will be extended to include a discussion of other octahedral nickel (II) compounds, e.g., Ki in. $MgO.3$ “