X-ray study of surface layers of air-annealed Be12Ti and Be12V samples using synchrotron radiation

Titanium beryllide Be12Ti and vanadium beryllide Be12V are considered to be promising materials for advanced neutron multipliers in the helium-cooled breeding blanket of DEMO reactor. A study of the surface layers of oxidized beryllide specimens by means of powder X-ray diffraction technique is presented in this work. The phase composition of the near-to-surface layers of Be12Ti and Be12V specimens was investigated at the Single Crystal Diffraction (SCD) beamline at ANKA synchrotron facility after air-annealing at 800 °C. A high surface sensitivity of measurements was achieved at grazing incidence conditions by varying the incidence angle. Since beryllium has low values of X-ray absorption, the near-surface regions having depths from 2 up to 20 μm were investigated. The main objective of the work is the evaluation of composition of the reactant products which can influence the parameters of retention and release of radiogenic gases.

► Surface layers of air-annealed Be12Ti and Be12V samples were investigated.
► X-ray diffraction analysis using synchrotron radiation allowed the study of near-surface regions with the depths of a few microns.
► Presence of beryllium oxide BeO was found in all investigated surface layers of Be12Ti and Be12V samples.
► Volatilization of vanadium oxide V2O5 was observed from the surface of Be12V sample after annealing at 800 °C.