Atomistic defect structures of Co₃Ti containing boron, carbon and beryllium

Abstract

The lattice properties of the L1₂-type Co₃Ti alloys doped with boron, carbon and beryllium were investigated by the X-ray diffraction analysis. The solubility limits of boron, carbon and beryllium into the Co₃Ti were shown to be 3.0, 0.2, and 0.6 at%, respectively. It was shown that the doping of boron enhanced both of the lattice parameter and the atomic ordering of the alloy, while the doping of carbon or beryllium reduced both of them. Based on these experimental results and the consideration for size (difference) and energetics between the constituent atoms and the additive atoms, it was proposed that boron occupied on the octahedral interstitial site, and carbon and beryllium occupied on the substitutional sites of cobalt and titanium respectively.