X-ray absorption spectroscopy study of nanocrystalline Y2O3

Inga Jonane (ISSP UL EXAFS Spectroscopy Laboratory)

The properties of materials at nanoscale play nowadays more and more important role. In this presentation we will talk about yttrium oxide (Y2O3) nanoparticles which when embedded can improve the mechanical strength of oxide dispersion-strengthened (ODS) steels at high temperatures and/or under irradiation. This is an important parameter to build, for example, safe fusion reactor as well as time-resistant solar concentrator.

Our laboratory is involved in the international project “EUROfusion Enabling Research”, under which we investigate structural properties of nanocrystalline Y2O3 in order to address more challenging problem of complex oxides as Y2O3, Y2Ti2O7 and Y2TiO5 nanocrystals in ODS steel matrix. X-ray absorption spectroscopy and recently developed by us reverse Monte-Carlo method with evolutionary algorithm approach (RMC/EA) are promising methods for such materials study.

In this work we studied the local structure of nanocrystalline (2-50 nm) yttrium oxide (Y2O3) using different experimental (X-ray diffraction, Raman spectroscopy, X-ray absorption spectroscopy) and theoretical (Classical Molecular Dynamics (CMD) and reverse Monte-Carlo (RMC)) methods.

As a result, we reconstructed and analyzed the local structure characteristics of yttrium oxide as a function of nanoparticle size. The RMC/EA method was used for the first time for modelling the structure of real nanoparticles. So far, it has been successfully applied to crystalline compounds.