In this work, we investigated the effects of Ca²⁺ and Mg²⁺ ions and annealing temperature on the spectroscopic parameters of chromium‐doped yttrium aluminum garnet ceramics (Cr:YAG). Samples were obtained with either a separate or a simultaneous addition of calcium and magnesium oxides. To achieve this, aqueous suspensions were prepared using Y₂O₃, Al₂O₃, Cr₂O₃, MgO, and CaO high‐purity powders as raw materials. The obtained suspensions were freeze‐granulated, pressed into pellets, debinded, and subjected to reactive sintering in vacuum at 1715°C for 6 h. Each material was annealed in air with temperatures between 1300 and 1700°C. Samples were also compared to Cr:YAG ceramics with the addition of silica as a sintering aid. All the materials obtained were then exposed to 445 nm excitation, and emission spectra in the visible and infrared wavelengths were recorded. The results showed that the emission spectra of Cr:YAG ceramics varied according to the annealing conditions: as‐sintered samples exhibited strong emissions of around 680 nm and, after air annealing, of around 1400 nm. This phenomenon is attributed to the Cr³⁺→Cr⁴⁺ transition. Samples doped solely with MgO exhibited the highest emission intensity in the infrared region. Thus, Mg²⁺ ions provided the best conversion efficiency of chromium ions.

中文翻译：

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Ca2 +和Mg2 +离子对掺铬钇铝石榴石陶瓷的烧结和光谱性能的影响

在这项工作中，我们研究了Ca ²⁺和Mg ²⁺离子以及退火温度对掺铬钇铝石榴石陶瓷（Cr：YAG）光谱参数的影响。通过分别或同时添加氧化钙和氧化镁获得样品。为此，使用Y ₂ O ₃，Al ₂ O ₃，Cr ₂ O ₃制备水悬浮液。，MgO和CaO高纯粉末为原料。将获得的悬浮液冷冻制粒，压成丸粒，脱粒，然后在真空中于1715°C进行反应烧结6小时。每种材料在1300至1700°C的温度下在空气中退火。还将样品与添加了二氧化硅作为烧结助剂的Cr：YAG陶瓷进行了比较。然后将获得的所有材料暴露在445 nm激发下，并记录可见光和红外波长的发射光谱。结果表明，Cr：YAG陶瓷的发射光谱随退火条件的不同而变化：烧结后的样品表现出大约680 nm的强发射，并且在空气退火后显示出大约1400 nm的强发射。这种现象归因于Cr ³⁺ →Cr ⁴⁺过渡。仅掺杂了MgO的样品在红外区域显示出最高的发射强度。因此，Mg ²⁺离子提供了最佳的铬离子转化效率。