Beryllium nitride: an alternative material to beryllium for extreme ultraviolet and soft X-ray uses

Abstract Extreme ultraviolet and soft X-ray optical systems require low absorbing materials for many technological applications. In this paper, the optical properties of beryllium nitride (Be3N2) are studied and compared with those of beryllium (Be), a widely used material in this context. Thus, the dielectric function of Be and Be3N2 are determined in the 4–100 eV energy interval by means of reflection electron energy loss spectroscopy. It is found that the absorption coefficient of Be and Be3N2 are similar in the 40–100 eV energies range. Thereafter, the superior chemical stability and mechanical properties of Be3N2 makes it a promising Be substitute as optical material in severe environments.