Radiation damage of MoAlB at elevated temperatures: Investigating MAB phases as potential neutron shielding materials. Issue 4 (April 2022) - Zhang, Dongya
Highlights: MAlB phases have a high neutron shielding capacity, especially for low-energy neutrons, compared to present shielding materials. MoAlB has a strong resistance to crack formation and amorphization under higher temperatures. The lattice parameter changes are related to the formation of point defects, which was evidenced by refinement of the GIXRD and DFT. Abstract: A new family of ternary nano-laminated compounds, MAB phases, are studied as a promising class of neutron shielding materials for applications within fusion reactors. The shielding capacity against high-energy neutrons was evaluated, and the damage tolerance of MoAlB against Si + irradiation was investigated over the temperature range of RT- 600 °C. The linear attenuation coefficients of these materials over wide neutron-energy ranges imply that Mo(W)AlB have a high neutron shielding capacity. MoAlB shows a strong resistance to crack formation and excellent tolerance to amorphization under higher temperatures. The detailed thermal dynamic behaviors (reaction barrier and migration barrier) associated with the defects in MoAlB were studied through DFT calculations. Also, the lattice parameter changes are related to the formation of various point defects and the defect evolution evidenced by Rietveld refinement of the GIXRD and DFT calculations. MoAlB is confirmed to be a great candidate as a neutron shielding material.