Determination of in-depth damaged profile by Raman line scan in a pre-cut He2+ irradiated UO2

Abstract

International audienc

Redox response of actinide materials to highly ionizing radiation

“…14) and UO 2 (ref. 43), while Al 2 O 3 has been shown to undergo both reduction 44 and anion-selective defect accumulation 45 . Anion segregation, accompanied by chemical reduction, has also been observed in Al 2 O 3 irradiated with an ultrafast laser 46 , which, similar to high-energy heavy ions, deposits energy in a material via electronic excitation.…”

Advanced techniques for characterization of ion beam modified materials

“…Utilizing complementary analytical techniques described in this article (RBS and XRD) and electron microscopy techniques [17,18], Raman spectroscopy studies have revealed ion-induced structural modifications (defects, distortion of bonds, fluorite phase transformation and amorphization) in binary oxides, such as zirconia [40], ceria and urania [41], and more complex oxides, such as pyrochlores [39,43]. In nanocrystalline monoclinic ZrO 2 thin films, Raman spectroscopy has been utilized to characterize the structural changes and phase evolution as a function of increasing fluence induced by the swift heavy ion irradiation [40].…”

“…As a result of the interaction of the laser light with molecular vibrations, phonons or other excitations, the energy of the laser photons can be shifted up or down, which then contains information about the vibrational modes in the sample. Raman spectroscopy has been increasingly applied for the structural characterization of ion-beam modified materials, such as in carbides [36][37][38] and oxides [39][40][41][42]. More recently, micro-Raman spectroscopy has been used to characterize the damage created over the entire ion range [36,41,42] to provide new information on quantification of the damage and structure modification as a function of depth, and on enlightenment of possible synergistic effects due to both nuclear and electronic energy deposition to the materials [31].…”

“…One of the recent developments includes an in situ Raman setup coupled with a cyclotron accelerator developed at CEMHTI laboratory (Orléans, France) that allows direct monitoring of the irradiation-induced changes in solid samples and at solid/fluid interfaces in real time [41,42]. Uranium dioxide (UO 2 ) is currently the standard fuel used in light water reactors, and its response to ion Detailed scattering geometry and data analysis can be found in Ref.…”

“…Such conventional use of Raman spectroscopy does not allow probing depths exceeding several micrometers and especially does not provide quantitative analysis at a fixed damage level. Recent developments have shown that micro-Raman can be employed to quantify the damage in the wake of energetic ions from the surface of a crystal to the depth at which the ions come to rest (tens of micrometers) by analyzing thin cross sections of irradiated bulk samples [36,38,41,42]. Such cross-sectional approach provides several salient outcomes, such as distinctive effects of nuclear and electronic mechanisms resulting from the ion slowing down processes and information regarding the final structure of ion-irradiated materials along the ion path.…”