Influence of antiphase boundary period parameter M′ on elastic and electronic properties of one dimensional long period structures of Al3Ti

Influence of antiphase boundary period parameter M′ on elastic and electronic properties of seven one dimensional long period structures of Al3Ti have been systematically investigated. With increase of M′, elastic constant C11 is decreased, whereas C12, C44 and C66 are increased. And elastic moduli G and E are also increased. Moreover, along principle axis, Ga is increased while Gc/Ga is decreased. Oppositely, Ea is decreased while Ec/Ea is increased. Two-dimensional directional dependence G and E further demonstrate the elastic anisotropy is enlarged. Electronic structures show that metallic bonding is weakened leading to poor ductility, and covalent bonding is enhanced resulting in larger stiffness.