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dc.contributor.advisor Ngoepe, P.E. Phasha, Maje Jacob
dc.contributor.other Pettifor, D.G. 2013-07-11T12:25:45Z 2013-07-11T12:25:45Z 2005
dc.description Thesis (M.Sc. (Physics)) --University of Limpopo, 2005 en_US
dc.description.abstract Self-consistent electronic structure calculations have been performed on ordered cubic-based magnesium-lithium (Mgx-Li1−x) alloys spanning the concentration range 0 ≤ x ≤ 1, using an ab initio plane wave pseudopotential (PWP) method. The first principle pseudopotential planewave approach is used within the local density approximation (LDA) and generalized-gradient approximation (GGA)of the density functional theory (DFT) framework. We have calculated the binding energy curves and the systematic trends in various cohesive and elastic properties at zero temperature, as a function of Li concentration. The calculated equilibrium lattice parameters show a large deviation from Vegard’s rule in the Li-rich region whilst the bulk moduli decrease monotonically with increase in Li concentration. The heats of formation for different ground state superstructures predict that the DO3, B2 and DO22 structures would be the most stable at absolute zero amongst various phases having the Mg3Li, MgLi and MgLi3 compositions, respectively. This stability is reflected in the electronic density of states (DOS). Because of the special significance of the isotropic bulk modulus, shear modulus, Young’s modulus and Poisson’s ratio for technological and engineering applications, we have also calculated these quantities from the elastic constants. The elastic constants indicate the softness of the material as more Li is added with the bcc-based phases becoming mechanically less stable for Li concentration less than 50%. Our results show good agreement within the estimated uncertainty with both experimental and previous theoretical results. en_US
dc.description.sponsorship The National Research Foundation (NRF), South Africa-Royal Society (RS), Great Britain collaboration and Council for the Scientific and Industrial Research (CSIR) en_US
dc.format.extent 114 leaves en_US
dc.language.iso en en_US
dc.publisher University of Limpopo (Turfloop Campus) en_US
dc.relation.requires pdf en_US
dc.subject Magnesium-lithium alloys Elastic properties en_US
dc.subject Cubic-based Mg-Li alloys en_US
dc.subject.ddc 669.72 en_US
dc.subject.lcsh Magnesium-lithium alloys en_US
dc.title Ab initio study of cohesive, electronic and elastic properties of ordered cubic-based Mg-Li alloys en_US
dc.type Thesis en_US

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