Vigier Jean-François, Popa Karin, Martel Laura, Manara Dario, Dieste Blanco Oliver, Freis Daniel, Konings Rudy J M
Joint Research Centre (JRC) , European Commission , P.O. Box 2340, 76125 Karlsruhe , Germany.
Inorg Chem. 2019 Jul 15;58(14):9118-9126. doi: 10.1021/acs.inorgchem.9b00679. Epub 2019 Jun 27.
Both AmAlO and PuAlO perovskites have been synthesized and characterized using powder X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and Al magic angle spinning nuclear magnetic resonance spectroscopy (MAS NMR). AmAlO perovskite showed a rhombohedral configuration (space group 3̅) in agreement with previous studies. The effect of americium α-decay on this material has been followed by XRD and Al MAS NMR analyses. In a first step, a progressive increase in the level of disorder in the crystalline phase was detected, associated with a significant crystallographic swelling of the material. In a second step, the crystalline AmAlO perovskite was progressively converted into amorphous AmAlO, with a total amorphization occurring after 8 months and 2 × 10 α-decays/g. For the first time, PuAlO perovskite was synthesized with an orthorhombic configuration (space group ), showing an interesting parallel to CeAlO and PrAlO lanthanide analogues. High-temperature XRD was performed and showed a → 3̅ phase transition occurring between 473 and 573 K. The thermal behavior of 3̅ PuAlO was followed from 573 to 1273 K, and extrapolation of the data suggests that cubic plutonium perovskite should become stable at around 1850 K (3̅ → 3̅ transition).
已通过粉末X射线衍射（XRD）、拉曼光谱、傅里叶变换红外光谱（FT-IR）和铝魔角旋转核磁共振光谱（MAS NMR）对AmAlO和PuAlO钙钛矿进行了合成和表征。AmAlO钙钛矿呈现出菱面体构型（空间群3̅），这与先前的研究一致。通过XRD和Al MAS NMR分析追踪了镅α衰变对该材料的影响。第一步，检测到晶相无序程度逐渐增加，这与材料显著的晶体学膨胀有关。第二步，结晶的AmAlO钙钛矿逐渐转变为非晶态AmAlO，在8个月和2×10α衰变/克后发生完全非晶化。首次合成了具有正交构型（空间群）的PuAlO钙钛矿，显示出与CeAlO和PrAlO镧系类似物有趣的相似性。进行了高温XRD，结果表明在473至573 K之间发生了3̅→3̅相变。从573至1273 K追踪了3̅ PuAlO的热行为，数据外推表明立方钚钙钛矿在约1850 K（3̅→3̅转变）时应变得稳定。
