Abstract
The β′ phase precipitate in Mg–Gd alloy system has been investigated by means of first-principles calculation within the generalized gradient approximation. The lattice parameters are determined theoretically by structural optimization of full relaxation, and the Mg 7Gd is found to be energetically more stable compared with the Mg 15Gd from the calculated formation energy. The nine independent elastic constants are calculated, indicating the proposed Mg 15Gd structure in literature is mechanically unstable. Then the polycrystalline bulk modulus B, Young's modulus E, shear modulus G, Poisson ratio ν of Mg 7Gd are gained by the Voigt–Reuss–Hill (VRH) approximation. The ductility and plasticity, especially elastic anisotropy are discussed in details. Based on the electronic density of states and charge density distribution, the covalent bonding and metallic bonding are exhibited in Mg 7Gd compound. Last, the Debye temperature is also calculated for the investigation in the future.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
