Plutonium and americium aluminate perovskites

Both AmAlO3 and PuAlO3 perovskites have been synthesised and characterised using powder X Ray Diffraction (XRD), Raman spectroscopy, Fourier-transform infrared spectroscopy (FT IR) and 27Al Magic Angle Spinning - Nuclear Magnetic Resonance spectroscopy (MAS-NMR). AmAlO3 perovskite showed a rhombohedral configuration (Space group R-3c) in agreement with previous studies. The effect of americium alpha-decay on this material has been followed by XRD and 27Al MAS-NMR analyses. In a first step, a progressive increase of disorder in the crystalline phase was detected, associated with a significant crystallographic swelling of the material. In a second step the crystalline AmAlO3 perovskite was progressively converted into amorphous AmAlO3, with a total amorphisation occurring after 8 months and 2 x 1018 alpha-decay/g. For the first time, PuAlO3 perovskite was synthesised with an orthorhombic configuration (Space group Imma), showing an interesting parallel to CeAlO3 and PrAlO3 lanthanide analogues. High-temperature XRD was performed and showed a phase transition Imma→R-3c occurring between 473 K and 573 K. The thermal behaviour of R-3c PuAlO3 was followed from 573 K to 1273 K, and extrapolation of the data suggests that cubic plutonium perovskite should become stable at around 1850 K (R-3c→Pm-3m transition).

VIGIER Jean-Francois;  POPA Karin;  MARTEL Laura;  MANARA Dario;  DIESTE BLANCO Oliver;  FREIS Daniel;  KONINGS Rudy; 

2019-07-24

AMER CHEMICAL SOC

JRC116024

0020-1669 (online),   

https://publications.jrc.ec.europa.eu/repository/handle/JRC116024,   

10.1021/acs.inorgchem.9b00679 (online),