Knowledge Bank

Strong sharp-line luminescence has been observed for the 5d$\mathrm{<mrow\; data-mjx-texclass="ORD">4</mrow>}$ $Os4+$ion as an impurity in single cubic crystals of the host lattice $Cs2ZrCl6$ at $20\circ K$. In the visible and near infrared regions luminescence occurs within the $t2g4$ configuration between the $\Gamma 1(1A1g)$ excited electronic state at 17 069 $cm-1$ and the four spin-orbit components of the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}T1g$ ground electronic state at 0, 2777, 4873, and 4972 $cm-1$. Each of these transitions is rich in vibrational structure. The detailed vibronic structure has been assigned on the basis of a phonon density of states calculation and the Jahn-Teller effect. Similar results have been obtained for the 5d$\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}$ $RE+4$ ion.