Characterization of radiation damage in ceramics: Old challenge new issues?

Abstract

This work is an overview of the physical approaches required for characterizing and understanding the long-term evolution of ceramics under irradiation. Because this subject is complex and has many ramifications, we have chosen to address the problem by looking at the behavior of a number of key ceramics. In the first part of this work, we present the physical mechanisms responsible for the production of primary defects, pointing out the main differences between metals, semiconductors, and insulators. In part two, we attempt to show how devoted experimental techniques can combine with transmission electron microscopy and x-ray techniques to provide a clearer picture of the long-term evolution of the microstructure of ceramics under irradiation. The last part of this work is devoted to discussing different approaches to explain and describe the long-term behavior of irradiated ceramics.

Phase field modelling of irradiated materials

“…From the analysis of different factors structures, it becomes possible to compute the evolution of k 0 versus R for given ∆ values as displayed in Figure 2. This evolution extracted from full PF simulation shows a clear linear evolution of k 0 with R −1 in agreement with theoretical investigations [25]. Patterns produced under irradiation result from slow composition modulations in space and time of simple basic patterns defined by the wave vector of modulus q 0 minimizing L. Although each individual stationary pattern breaks transitional and rotational symmetries (Fig 3), different patterns grow in different parts of the system implying the formation of various defects connecting these different steady states [9] as displayed in Fig 3. From the stationarity of L, it is possible to compute all possible micro-structures produced in a pattern domain as a function of the overall concentration of the alloys (ψ in reduced unit) as well as a function of ∆ and R noted as displayed in Fig.3.…”

“…where t * k are reciprocal lattice vectors of the parent crystal phase [27,28] Breaking the translation symmetry in the amorphous phase leads to the existence of an internal stress field associated with topological defects and function of the order parameter within the Phase Field framework. Such an approach may be useful to explain radiation induced amorphization observed in many alloys and ceramics [25,29].…”

Symmetry Breaking Resulting from Long-Range Interactions in Out of Equilibrium Systems: Elastic Properties of Irradiated AgCu

“…Atomic scale methods alone cannot provide such information due to the long-range nature of elastic interactions. By its ability to take these interactions into account in systems maintained far from equilibrium, such an approach could be applied for instance to the study of mixed oxide nuclear fuels [43].…”

Radiation-Induced Effects on Material Properties of Ceramics: Mechanical and Dimensional Properties

“…The displacement energy (Ed) of constituent ions is one of the most important parameter to describe radiation effects in ceramic compounds, and values of Ed in some limited ceramic compounds were summarized in review papers. 12,30,48 A number of experimental and theoretical evaluations of Ed were reported for fluorite-type oxides, such as by optical measurements, transmission electron microscopy (TEM), EPR, empirical MD and ab initio MD simulations. 41,43,[49][50][51][52][53][54][55] Table 1 summarizes the reported Ed values of several fluorite-type oxides for cations and oxygen ions.…”

“…24 It is worthwhile to note that there are excellent books and reviews for radiation effects in ceramics. 12,15,[25][26][27][28][29][30] Thanks to the achievements of those articles, we will review the defect production, migration, formation of extended defects, accumulation of defects of those three types of ceramic compounds (that is, fluorite-type oxides, silicon carbide and magnesium aluminate spinel), with emphasizing the similarity and difference of these materials, to lead to the discussion on the dimensional stability and mechanical properties of ceramics.…”