Luminescent properties of MgWO4 crystals

Abstract

Luminescent properties of magnesium tungstate were investigated. Two samples of MgWO4 single crystals grown by different methods were studied. Only intrinsic luminescence attributed to exciton emission was detected for the both samples and. It was shown that the temperature dependence of the low-energy edge in the excitation spectra obeys Urbach rule. Steepness coefficient that was deduced from this dependence indicates self-trapping of excitons in MgWO4. The absence of cation d states in the valence band is a distinctive feature of MgWO4 that is shown to be manifested in the luminescence excitation spectra.