First-principles Study of NiAl Alloyed with Rare Earth Element Ce

The structural, elastic, and electronic properties of NiAl alloyed with rare earth element (REE) Ce have been investigated by using density functional theory (DFT). It is found that Ce has a strong AI site preference and causes lattice distortion of NiAl. The calculation of elastic constants shows that Ce increased both the hardness and the ductility of NiAl, which could be explained by the formation of new ionic bonds between AI (and Ni) and Ce and the enhancement of covalent bonds in Ni8Al7Ce. Our results are in good agreement with the available experimental data and other theoretical results.