Theoretical prediction on the stability, elastic, electronic and optical properties of MAB-phase M 4 AlB 4 compounds (M = Cr, Mo, W).

This research employs first-principles calculations to address the challenges presented by processing complexity and low damage tolerance in transition metal borides. The study focuses on designing and investigating MAB phase compounds of M 4 AlB 4 (M = Cr, Mo, W). We conduct a comprehensive assessment of the stability, phononic, electronic, elastic, and optical properties of Cr 4 AlB 4 , Mo 4 AlB 4 , and W 4 AlB 4 . The calculated results reveal formation enthalpies of -0.516, -0.490, and -0.336 eV per atom for Cr 4 AlB 4 , Mo 4 AlB 4 , and W 4 AlB 4 , respectively. Notably, W 4 AlB 4 emerges as a promising precursor material for MABene synthesis, demonstrating exceptional thermal shock resistance. The dielectric constants ε 1 (0) were determined as 126.466, 80.277, and 136.267 for Cr 4 AlB 4 , Mo 4 AlB 4 , and W 4 AlB 4 , respectively. Significantly, W 4 AlB 4 exhibits remarkably high reflectivity (>80%) within the wavelength range of 19.84-23.6 nm, making it an ideal candidate for extreme ultraviolet (EUV) reflective coatings. The insights gleaned from this study provide a strong research framework and theoretical guidance for advancing the synthesis of innovative MAB-phase compounds.