RADIATION DAMAGE IN ION-IRRADIATED CeO2 AND (Ce, Gd)O2 SINTERS: EFFECT OF THE Gd CONTENT
RADIATION DAMAGE IN ION-IRRADIATED CeO2 AND (Ce, Gd)O2 SINTERS: EFFECT OF THE Gd CONTENT
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DOI：
10.1016/j.jnucmat.2022.153667
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发表时间：
2022-03
影响因子：
3.1
通讯作者：
J. Costantini;G. Gutierrez;Gérald Lelong;M. Guillaumet;Pooreun Seo;K. Yasuda
中科院分区：
文献类型：
--
作者：
J. Costantini;G. Gutierrez;Gérald Lelong;M. Guillaumet;Pooreun Seo;K. Yasuda
用显微拉曼光谱和紫外-可见漫反射光谱研究了CeO 2和Ce-Gd复合氧化物（Ce，Gd）O2-x的辐射损伤。在室温下用2.5-MeV Ar 2+和12-MeV Ar 4+离子以高能量密度（即分别为5 × 1014 cm − 2和2.1 × 1014 cm − 2）辐照未掺杂CeO 2和（Ce，Gd）O2-x（Gd 2 O3的摩尔分数分别为1%和5%）的烧结样品。拉曼光谱表明，无论Gd含量如何，这些氧化物都没有发生非晶化。从F2 g峰强度随注量的衰减曲线可以看出，损伤截面随Gd ~（3+）含量的变化不明显。此外，反射率谱显示出明显的带隙能量的减少和增加的Urbach能量所产生的点缺陷积累。对于1摩尔%和5摩尔%的Gd 2 O3，发现了类似的效果，而对于未掺杂的氧化铈，看到了对带拖尾的较大影响。核碰撞和电子激发各自的作用进行了讨论，知道这两种测量不探测相同的样品深度的离子能量。Gd 3+离子取代Ce 4+离子可能减少损伤和与通过电子激发过程形成Ce 3+离子相关的带尾的形成。
The radiation damage induced in cerium dioxide CeO2and cerium-gadolinium mixed oxides (Ce, Gd)O2-xwas studied by micro-Raman spectroscopy and diffuse UV-visible reflectance spectroscopy. Sintered samples of undoped CeO2and (Ce, Gd)O2-xfor 1 mol% and 5 mol% of Gd2O3were irradiated at room temperature with 2.5-MeV Ar2+and 12-MeV Ar4+ions up to high fluences (i.e. 5 × 1014cm−2and 2.1 × 1014cm−2respectively). The Raman spectra show that no amorphization of those oxides occurs whatsoever, regardless of the Gd content. No clear change of the damage cross section with the Gd3+content is deduced from the decay of F2gpeak intensity versus fluence. Moreover, the reflectivity spectra show a clear decrease of the band-gap energy and increase of the Urbach energy arising from point defect accumulation. Similar effects are found for 1 mol% and 5 mol% Gd2O3, whereas a larger effect on band tailing is seen for undoped ceria. The respective roles of nuclear collisions and electronic excitations are discussed for both ion energies knowing that the two kinds of measurements do not probe the same sample depth. The substitution of Gd3+ions for Ce4+ions is likely reducing the damage and the formation of band tails related to the formation of Ce3+ions by electronic excitation processes.