Fabrication and luminescent properties of erbium‐doped Y ₂ O ₃ –MgO and Gd ₂ O ₃ –MgO nanocomposite ceramics

We report on the fabrication and optical properties of erbium‐doped Y 2 O 3 –MgO and Gd 2 O 3 –MgO nanocomposite ceramics, with a particular focus on their mid‐infrared emission. The ceramics were fabricated by a self‐propagating high‐temperature synthesis followed by hot pressing. The transmittance of 1.7 mm‐thick 5 at.% Er:Y 2 O 3 –MgO and 7 at.% Er:Gd 2 O 3 –MgO ceramics at 3 µm amounted to 79.4% and 21.5%, respectively. This difference in transmission, as revealed by microstructural analysis, is due to variation in the distribution of residual pore sizes, while the average grain size is almost the same for both ceramics, being ∼200 nm. The composites exhibited luminescence in the visible, near‐infrared, and mid‐infrared spectral ranges attributed to electronic transitions of Er 3+ ions in the cubic sesquioxide phase. Peculiarities in the Raman and luminescence spectra were identified in comparison to single‐phase Er:Y 2 O 3 and Er:Gd 2 O 3 ceramics, which may indicate certain solubility of MgO in the sesquioxide phase of the composites.