Structural and Optical Properties of Highly Nd‐Doped Yttrium Aluminum Garnet Ceramics from Alkoxide and Glycolate Precursors
Structural and Optical Properties of Highly Nd‐Doped Yttrium Aluminum Garnet Ceramics from Alkoxide and Glycolate Precursors
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DOI：
10.1111/j.1551-2916.2006.01000.x
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发表时间：
2006-06
影响因子：
3.9
通讯作者：
S. Mathur;Hao Shen;M. Veith;R. Rapalaviciute;T. Agne
中科院分区：
文献类型：
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作者：
S. Mathur;Hao Shen;M. Veith;R. Rapalaviciute;T. Agne
通过对 (i) 醇盐前体和 (ii) 阳离子与聚乙二醇络合形成的金属螯合物进行溶胶-凝胶处理，合成了掺杂高钕 (Nd) 含量 (3 at.%) 的钇铝石榴石 (YAG) 纳米粉末。按照这两个步骤获得了化学计量的 YAG 组合物；然而，乙醇酸酯合成中颗粒的团聚程度明显更高，这可以保护残留有机物免遭氧化（元素分析）。 Nd:YAG 陶瓷的泵浦能量吸收和光致发光光谱表明，Nd3+ 离子在 YAG 基质中的分布在醇盐衍生粉末中更加均匀。乙醇酸盐衍生样品中 Nd 中心的偏析得到了烧结过程中 Nd2O3 结晶相（X 射线衍射）沉淀的支持。粉末的高分辨率吸收光谱（4I9/2(1)→4F9/2(1)）表明，乙醇酸衍生的粉末具有较高的吸收截面，这是由于Nd3+–Nd3+离子配对导致的光致发光猝灭。由于光学活性中心更好的分散，醇盐衍生的 Nd:YAG 陶瓷的光致发光信号显着增强。
Yttrium aluminum garnet (YAG) nanopowders doped with high neodymium (Nd) content (3 at.%) were synthesized by the sol–gel processing of (i) alkoxide precursors and (ii) metal chelates formed by complexing the cations with polyethylene glycol. A stoichiometric YAG composition was obtained following both procedures; however, the agglomeration of particles was significantly higher in glycolate synthesis, which shielded residual organics from oxidation (elemental analyses). Distribution of Nd3+ ions in the YAG matrix, as shown by the absorption of pump energy and photoluminescence spectra of Nd:YAG ceramics, was more homogeneous in alkoxide-derived powders. The segregation of Nd centers in the glycolate-derived sample was supported by the precipitation of a crystalline Nd2O3 phase (X-ray diffraction) during sintering. High-resolution absorption spectra (4I9/2(1)→4F9/2(1)) of the powders showed that a higher absorption cross-section of glycolate-derived powders is due to Nd3+–Nd3+ ion pairing, which leads to the quenching of photoluminescence. Owing to the better dispersion of optically active centers, the photoluminescence signal was found to be substantially enhanced in alkoxide-derived Nd:YAG ceramics.