X-ray diffraction study of δ-stabilized plutonium alloys under pressure

Previous extensive Studies of the delta --> alpha'-phase transformation induced by temperature and/or by pressure in delta-stabilized Plutonium alloys indicate strong dependence on parameters such as solute type, solute distribution, chemical impurities, kinetics, thermodynamic path .... The present paper reports results obtained on two Pu-2.3at.%Ga binary alloys differing by Solute homogenization treatment and studied under pressure by in situ by X-ray diffraction in diamond anvil cells. The gamma'-phase appears as an intermediate phase during the delta --> alpha'-phase transformation. In cored samples, unexpanded alpha'-phase is formed at the beginning of the transformation, from domains with low solute content, and expanded alpha'-phase subsequently forms (from domains with higher Solute content) as the transformation progresses with the pressure increase. (C) 2010 Elsevier B.V. All rights reserved.