| Abstract Scope |
Ti-doped transparent MgGa2O4 ceramics, possessing a high inversion level, compare to MgAl2O4, were fabricated by Pulsed Electric Current Sintering at 950 °C under vacuum for 30–90 min. Optical transmission, emission, and electron paramagnetic resonance spectra were recorded. The maximal transmission level was ~70%, for a thickness of ~1 mm, which, while not very high, permitted the observation of the optical absorption bands location and profile. Comparison of the Ti doped MgGa2O4 (high inversion) and MgAl2O4 (low inversion) spinels, spectral characteristics revealed that a significant increase in the inversion level drives Ti3+ cations from octahedral toward tetrahedral sites. Interpretation of the fluorescence spectra suggests Ti4+ cations (mostly hexacoordinated) were accommodated by the host-despite the scarcity of oxygen in the atmosphere during the sintering process. |