Neutron irradiations in oxidized lithium-doped MgO crystals

The effect of neutron irradiation on lithium-doped MgO crystals is investigated using optical-absorption and EPR measurements. Unlike electron irradiation, neutron irradiation does not produce stable ${\mathrm{}\left[\mathrm{Li}\right]\mathrm{}}^0$ centers in as-grown MgO: Li crystals. In crystals containing stable ${\mathrm{}\left[\mathrm{Li}\right]\mathrm{}}^0$ centers produced by oxidation at elevated temperatures, neutron irradiation results in a decrease of ${\mathrm{}\left[\mathrm{Li}\right]\mathrm{}}^0$ concentration and the formation of stable $V^0$, $V^{-}$, $V_{\mathrm{OH}}$, and $V_F$ centers. The loss of ${\mathrm{}\left[\mathrm{Li}\right]\mathrm{}}^0$ centers is attributed to the recombination of holes from these centers with electrons at multivacancy defects created by neutrons.