Microstructural, electronic, and mechanical properties of Al4La and Al4Sm intermetallics: An experimental and first-principles calculations

The crystal structure, elastic properties, and electronic structure of Al₄La and Al₄Sm intermetallics were systematically studied by both experimental (SEM, EDS, and nano-indentation) and theoretical methods (first-principle calculations). The microstructure of Al-10% La/Sm alloy exhibited a continuous reticular structure containing intermetallics with long needle-like shapes. The calculated lattice constants of Al₄La and Al₄Sm intermetallics were obtained through structural optimization and agreed with the results obtained by Rietveld refinement with an error of 4La and Al₄Sm was less than 7.3%. Further analysis of the elastic constants indicated that Al₄La has great plasticity and stiffness than Al₄Sm, while Al₄Sm showed a more anisotropic Young's modulus. Besides, Al₄La is found to perform better than Al₄Sm in plasticity and rigidity.