Time resolved luminescence spectroscopy of alkaline earth oxides after pulsed electron beam irradiation. II. Spectra and thresholds of MgO

Abstract

Time-resolved luminescence spectroscopy has been used to study the emissions occurring in MgO in the time range 100 ns to 100 μs after irradiation with nanosecond duration pulses of electrons of energy between 0.2 and 3.0 MeV. An emission at ∼380 nm with a threshold energy of 0.28±0.01 MeV is attributed to processes resulting from the displacement of oxygen anions and the formation of F+ centers. An emission at ∼240 nm is attributed to processes resulting from the displacement of magnesium cations, with a threshold energy of 0.32±0.01 MeV. An emission at ∼470 nm at an electron energy of 3.0 MeV is attributed to processes resulting from the formation of aggregates of F+ centers, such as the F2+2 center. Displacement energies of 49±2 and 38±2 eV were estimated for oxygen anions and magnesium cations, respectively.