Knowledge Bank

The photoexcitation and luminescence spectra $(2E⟶4A2)$ of $MnF6\mathrm{<mrow\; data-mjx-texclass="ORD">2-</mrow>}$ diluted in $Cs2GeF6$ and $K2GeF6$ host lattices have been recorded at liquid helius temperature. The manganese coordination geometry is Oh, in $Cs2GeF6$ and $D3d$ in $K2GeF6$. Optically detected magnetic resonance (ODMR) has been employed to determine the g-value of the $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}E$ state in both coordination geometries. The trigonal distortion has a pronounced effect on the g-values and produces a measurable splitting in the optical spectrus, but exerts relatively little effect on the radiative lifetime. In particular. the g-value in the oh site $(g(2E)-2.0)$ is as predicted theoretically; however, the value obtained for the D3d site is unexpectedly large $(g(2E)-2.95)$. The data obtained is compared with theoretical predictions and the results of similar studies of $d3$ ions in a variety of lattices. The differences are shown to arise, in part, from the relative magnitude of the spin-orbit coupling and the trigonal field splitting in the $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}E$ state