Preparation, structure analysis and photoluminescence properties of MgGa2O4:Mn

In this work the photoluminescence and excitation spectra at room temperature of the spinel-type MgGa₂O₄ with 0.5% and 10.0% of Mn²⁺ have been studied. The polycrystalline samples were synthesized by standard solid-state reaction methods at high temperature. The photoluminescence spectra exhibit green and red emissions for both samples, attributed to ⁴T₁(⁴G) → ⁶A₁(⁶S) transition of Mn²⁺ ion in tetrahedral and octahedral sites of oxygen, respectively. The excitation spectra exhibit features unambiguously assigned to d–d transitions of Mn²⁺ in those kinds of sites. From the excitation spectra and Tanabe–Sugano matrices the crystal field Dq and Racah B parameters were obtained.