Abstract Yttrium aluminum garnet ceramics with a wide range of technological and industrial applications have attracted great attention owing to their remarkable mechanical, thermal and optical features. The properties of transparent or translucent YAG ceramics with wide-ranging applications notably depend on the features of the starting particles which is directly affected by synthesis conditions. In this study, yttrium aluminum garnet precursors (YAG) were obtained by reverse co-precipitation method from a mix solution of aluminum and yttrium nitrates using ammonium hydrogen carbonate (AHC) and ammonia water (AW) solutions as precipitator agents. The effect of pH on the chemical composition and phase analysis of the precursors synthesized by different precipitants was explored, leading to the formation of precursors with the proper stoichiometric ratio of YAG phase. The phase evaluation process, thermal behavior, microstructures and other characteristics were compared for the two precipitants by ICP, XRD, FTIR, TG-DTA, BET, FESEM, TEM and EDX analysis. The results revealed that unlike AW, using AHC as precipitant at high pH values caused deviation from the YAG stoichiometric ratio. In the pH value of 7, both precipitants produced homogenous precipitates and pure YAG at a calcination temperature of 900 °C while the powders obtained by AHC exhibited more dispersity and fewer aggregates. Sub-micron-grained YAG ceramics were obtained by SPS method at 1380 °C for 10 min using amorphous nano particles without adding any sintering aids. Compared with ceramics produced using synthesized powders by AW, the ceramic of co-precipitated powders by AHC showed higher density (99.9%) and transparency (33% at 680 nm and 50% at 1100 nm).

中文翻译：

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改变pH值和沉淀剂合成和放电等离子体烧结YAG纳米颗粒的比较

摘要 钇铝石榴石陶瓷由于其显着的机械、热学和光学特性，在技术和工业应用方面具有广泛的应用前景。具有广泛应用的透明或半透明 YAG 陶瓷的性能主要取决于合成条件直接影响的起始颗粒的特性。在这项研究中，使用碳酸氢铵 (AHC) 和氨水 (AW) 溶液作为沉淀剂，通过反向共沉淀法从铝和硝酸钇的混合溶液中获得了钇铝石榴石前驱体 (YAG)。探讨了pH值对不同沉淀剂合成的前驱体化学成分和相分析的影响，导致形成具有适当化学计量比的 YAG 相的前体。通过ICP、XRD、FTIR、TG-DTA、BET、FESEM、TEM和EDX分析对两种沉淀剂的物相评价过程、热行为、微观结构和其他特性进行了比较。结果表明，与 AW 不同，在高 pH 值下使用 AHC 作为沉淀剂会导致偏离 YAG 化学计量比。在 pH 值为 7 时，两种沉淀剂均在 900 ℃的煅烧温度下产生均匀的沉淀物和纯 YAG，而 AHC 获得的粉末表现出更好的分散性和更少的聚集体。使用无定形纳米颗粒，在不添加任何烧结助剂的情况下，通过 SPS 方法在 1380°C 下 10 分钟获得亚微米晶粒的 YAG 陶瓷。与使用 AW 合成粉末生产的陶瓷相比，