Effect of counter ions on the reduction process of Sm3+ ions in TiO2–ZrO2–Al2O3–SiO2 glasses
Effect of counter ions on the reduction process of Sm3+ ions in TiO2–ZrO2–Al2O3–SiO2 glasses
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DOI：
10.1016/j.jallcom.2004.11.084
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发表时间：
2006-02
影响因子：
6.2
通讯作者：
G. Kawamura;T. Hayakawa;M. Nogami
中科院分区：
文献类型：
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作者：
G. Kawamura;T. Hayakawa;M. Nogami
用荧光光谱技术研究了xTiO_2（ZrO_2）-（10−x）Al_2 O_3 - 90 SiO_2（x=0-10mol%）玻璃中Sm ~（3+）还原的放化反应，其荧光强度分别为560- 650 nm（Sm ~（3+）; 4G ~（5/2）→ 6 H_J）和680- 720 nm（Sm ~（2+）; 5D ~（0）→ 7 F_J）。结果表明，引入TiO 2后，Sm ~（3+）离子在X射线辐照下的还原反应明显减弱，当TiO 2含量大于5%时，Sm ~（3+）离子在玻璃中没有发生还原反应。另一方面，在含ZrO 2的玻璃中，Sm 3+离子的还原几乎是单调的，直到ZrO 2的5%。电子自旋共振（ESR）谱显示存在一些缺陷中心：空穴陷阱中心（HTC）和电子陷阱中心（ETC）。被束缚在Al 3+离子上的氧离子捕获的空穴中心与Sm 3+到Sm 2+离子的还原过程密切相关;从Al相关的HTC释放的电子被最近的Sm 3+离子捕获，形成Sm 2+。另一方面，在含TiO 2的玻璃中，所产生的电子优选地被捕获在Ti 4+离子中以形成ETC，导致Sm 3+离子不还原。
The radio-chemical reaction of Sm3+reduction in xTiO2(ZrO2)–(10−x)Al2O3–90SiO2glasses (x=0–10mol%) was examined by a photoluminescence technique with fluorescence intensities at 560–650nm (Sm3+;4G5/2→6HJ) and 680–720nm (Sm2+;5D0→7FJ). It was found that the reduction of Sm3+ions by X-ray irradiation was significantly decreased by the introduction of TiO2and no reduction occurred in the glasses containing TiO2above 5%. On the other hand, in the ZrO2containing glasses, the reduction of Sm3+ions was almost monotonous up to 5% of ZrO2. Electron spin resonance (ESR) spectra revealed the presence of some defect centers; hole-trap center (HTC) and electron-trap center (ETC). Hole centers trapped by oxygen ions bound to the Al3+ions were strongly related to the reduction process from Sm3+to Sm2+ions; the released electrons from the Al-related HTC were captured by the nearest Sm3+ions, forming Sm2+. On the other hand, in the TiO2-containing glasses, electrons generated were preferably trapped in Ti4+ions so as to form ETC, resulting in no reduction of Sm3+ions.