Study of local ordering effects in irradiated VNbMoTaW by means of EXAFS.

Refractory high entropy alloys (RHEAs) have shown great potential to be used for material renewal in harsh environment industries and applications in space, accelerator physics and nuclear energy due to the superior stability and toughness at high temperature that surpass Ni-based super alloy. However, the radiation resistance underpinning mechanism is still an open question and requires a detailed understanding of the atomic-scale interstitial-defect-lattice interactions. Extensive theoretical and experimental studies are currently underway to understand and harness the role played by structural short range ordering to VNbMoTaW RHEA. In particular, state-of-the-art atomistic simulations predicted element specific local ordering and this proposal aims to confirm through EXAFS characterisation its existence and behaviour as a function of heavy self-ion irradiation fluence in the random system.