Lenz Christoph, Thorogood Gordon, Aughterson Robert, Ionescu Mihail, Gregg Daniel J, Davis Joel, Lumpkin Gregory R
Australian Nuclear Science and Technology Organisation, Sydney, NSW, Australia.
Institut für Mineralogie und Kristallographie, Universität Wien, Vienna, Austria.
Front Chem. 2019 Feb 5;7:13. doi: 10.3389/fchem.2019.00013. eCollection 2019.
In this study, we present a new concept based on the steady-state, laser-induced photoluminescence of Nd, which aims at a direct determination of the amorphous fraction in monazite- and xenotime-type orthophosphates on a micrometer scale. Polycrystalline, cold-pressed, sintered LaPO, and YPO ceramics were exposed to quadruple Au-ion irradiation with ion energies 35 MeV (50% of the respective total fluence), 22 MeV (21%), 14 MeV (16%), and 7 MeV (13%). Total irradiation fluences were varied in the range 1.6 × 10-6.5 × 10 ions/cm. Ion-irradiation resulted in amorphization and damage accumulation unto a depth of ~5 μm below the irradiated surfaces. The amorphous fraction created was quantified by means of surface-sensitive grazing-incidence X-ray diffraction and photoluminescence spectroscopy using state-of-the-art confocal spectrometers with spatial resolution in the μm range. Monazite-type LaPO was found to be more susceptible to ion-irradiation induced damage accumulation than xenotime-type YPO. Transmission electron microscopy of lamella cut from irradiated surfaces with the focused-ion beam technique confirmed damage depth-profiles with those obtained from PL hyperspectral mapping. Potential analytical advantages that arise from an improved characterization and quantification of radiation damage (i.e., ) on the μm-scale are discussed.
在本研究中，我们提出了一种基于钕的稳态激光诱导光致发光的新概念，旨在直接测定独居石型和磷钇矿型正磷酸盐中微米级的非晶态分数。将多晶、冷压、烧结的LaPO₄和YPO₄陶瓷用能量分别为35 MeV（占各自总注量的50%）、22 MeV（21%）、14 MeV（16%）和7 MeV（13%）的四重金离子进行辐照。总辐照注量在1.6×10⁻⁶ - 6.5×10⁻⁶离子/cm范围内变化。离子辐照导致在辐照表面以下约5μm深度处发生非晶化和损伤积累。通过使用具有微米级空间分辨率的先进共焦光谱仪的表面敏感掠入射X射线衍射和光致发光光谱对产生的非晶态分数进行定量。发现独居石型LaPO₄比磷钇矿型YPO₄更容易受到离子辐照诱导的损伤积累。用聚焦离子束技术从辐照表面切割薄片的透射电子显微镜证实了损伤深度分布与从光致发光高光谱映射获得的损伤深度分布一致。讨论了在微米尺度上改进辐射损伤（即 ）表征和定量所带来的潜在分析优势。
