The highly transparent novel high-entropy (Lu_0.2Y_0.2Gd_0.2Yb_0.2Er_0.2)₂O₃ ceramic was successfully fabricated by the addition of 3 at.% ZrO₂ and 10 at.% La₂O₃ introduced as sintering additives via vacuum sintering. A single-phase solid solution cubic structure of the ceramic was obtained with a relative density of 99.95 % and an average grain size of 6.91±3.28 µm. The grain boundary of the (Lu_0.2Y_0.2Gd_0.2Yb_0.2Er_0.2)₂O₃ ceramic was clean with a thickness of only 1.3 nm. Further observations revealed uniform distribution of all elements in the grains, and the presence of La and Zr segregation (1.5 nm thick) at few grain boundaries, but causing very little light scattering. The in-line transmittance of high-entropy (Lu_0.2Y_0.2Gd_0.2Yb_0.2Er_0.2)₂O₃ ceramic reached 80 % at 1100 nm, which was 98.7 % of the theoretical value of Er₂O₃ single crystal. Also, there were fluorescence emissions observed in the ultraviolet (311 nm), visible (563, 622 nm), and near-infrared (1032, 1535 nm) regions. In addition, the intense red emission and weak green emission were detected, and the broad emission with a peak at 1.5 μm was attributed to Stark splitting of Er³⁺ ions, so the corresponding mechanism was discussed. Results obtained suggest that the highly transparent novel high-entropy (Lu_0.2Y_0.2Gd_0.2Yb_0.2Er_0.2)₂O₃ ceramic fabricated in this study could have broad application prospects in optical applications such as scintillators, up-conversion luminescent materials, and infrared lasers.

中文翻译：

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高透明新型高熵（Lu0.2Y0.2Gd0.2Yb0.2Er0.2）2O3陶瓷的制备及发光性能


通过真空烧结添加 3 at.% ZrO₂ 和 10 at.% La₂O₃ 作为烧结添加剂，成功制备了高透明的新型高熵 （Lu_0.2Y_0.2Gd_0.2Yb_0.2Er_0.2） ₂O₃ 陶瓷。获得了陶瓷的单相固溶体立方结构，相对密度为 99.95 %，平均晶粒尺寸为 6.91±3.28 μm。（Lu_0.2Y_0.2Gd_0.2Yb_0.2Er_0.2）₂O₃陶瓷的晶界干净，厚度仅为 1.3 nm。进一步的观察揭示了晶粒中所有元素的均匀分布，并且在少数晶界处存在 La 和 Zr 偏析（1.5 nm 厚），但引起的光散射非常小。高熵 （Lu_0.2Y_0.2Gd_0.2Yb_0.2Er_0.2）₂O₃ 陶瓷在 1100 nm 处的直线透射率达到 80 %，是 Er₂O₃ 单晶理论值的 98.7 %。此外，在紫外 （311 nm）、可见光 （563、622 nm） 和近红外 （1032、1535 nm） 区域观察到荧光发射。此外，还检测到了强红光发射和弱绿光发射，峰在 1.5 μm 处的宽发射归因于 Er³⁺ 离子的 Stark 分裂，因此讨论了相应的机理。获得的结果表明，高度透明的新型高熵 （Lu_0.2Y_0.2Gd_0.2Yb_0.2Er_0.2）本研究制备的 ₂O₃ 陶瓷在闪烁体、上转换发光材料和红外激光器等光学应用中具有广阔的应用前景。