https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:15525 Tue 24 Aug 2021 14:38:53 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33512 Tue 13 Nov 2018 13:07:00 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33538 Thu 15 Nov 2018 14:09:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:8708 Sat 24 Mar 2018 08:41:28 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:17431 b structure of molybdenum disilicide are calculated by a direct Monte Carlo simulation technique. Correlation factors for Si diffusion on its sublattice are compared with literature values that were calculated using a more complicated Monte Carlo method based on the matrix approach. It is shown that there is no need for this complicated approach and that the direct Monte Carlo simulation technique gives highly accurate correlation factors. Correlation factors and anisotropy ratios of vacancy-mediated diffusion in both sublattices are deduced and compared with experimental data. Tracer correlation in the tetragonal direction is shown to contribute 0.40 eV (i.e. over 55%) of the migration energy of the corresponding Si diffusivity. Two possible jump rates for Si diffusion are separately estimated. Mo diffusion correlation factors are calculated using the direct Monte Carlo technique. A comparison with experiment is made and the ratio of two possible jump rates is also estimated.]]> Sat 24 Mar 2018 08:01:40 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:22642 ab initio calculations. The generated samples, the dimensionality of which was determined by appropriate periodic boundary conditions imposed upon the generated supercells, were initially either perfectly ordered in the c-variant L1₀ superstructure ((001)-oriented monatomic planes), or completely disordered in the fcc crystalline structure. Vacancy-mediated creation of equilibrium atomic configurations was modelled by relaxing the systems at temperatures below the 'order-disorder' transition point using the Glauber algorithm implemented with the vacancy mechanism of atomic migration. The (100)-type-surface-induced heterogeneous nucleation of L1₀-order domains was observed and quantified by means of an original parameterization enabling selective determination of volume fractions of particular L1₀-variants. Due to the specific competition between the three kinds of (100)-type free surfaces, the initial c-L1₀ variant long-range order appeared to be the most stable in the cubic nanoparticle. The initially disordered samples were transformed by the creation of a specific L1₀ domain structure with a mosaic of particular L1₀-variant domains at the surfaces and almost homogeneous long-range order in the inner volume. The analysis of correlation effects revealed that chemical ordering was initiated at the free surfaces.]]> Sat 24 Mar 2018 07:17:03 AEDT ]]>