First-principles calculation of dislocation properties of ductile rare-earth intermetallic compounds

We have used first-principles calculations to study the mechanical properpies of rare-earth intermetallic B2 compounds which exhibit significant ductility. According to Peierls-Nabarro model and slip plane observed in tensile experimens, we have calculated and compared the {110} gamma surface energy for both brittle NiAl and ductile YCu. We also compared unstable stacking fault and twinning energy for a series of B2 compounds with different ductilily. Correlation between these energetics and the ductilily are discussed.