Spin dynamics in the mixed-valence compound HgSe:Fe

We present for the first time the spin-Hamiltonian parameters of ${\mathrm{Fe}}^{3+}$ in HgSe. From the dependence of the broadening of the ${\mathrm{Fe}}^{3+}$ EPR lines on temperature in the range of 5-50 K we derive the exchange-interaction constant of conduction-band electrons and the iron spin for iron concentrations ranging from 5 × ${10}^{17}$ to 6 × ${10}^{18}$ ${\mathrm{cm}}^{-3\mathrm{}}$ and the spin-correlation time of conduction-band electrons is determined.