https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34299 −6) significantly extend the frequency range available for determining, in particular, the high temperature background of acoustic loss seen at temperatures greater than half the melting point. For Sn at T<450 K and Bi, the frequency dependence of the loss appears to follow fⁿ with n~0.2, assuming activation energies determined by lattice diffusion or pipe diffusion within dislocations. For Sn there appears to be a temperature interval up to the melting point with n≈1, which could be indicative of premelting. The same approach of using a soft metal matrix to support a second phase has also been demonstrated for measuring acoustic loss in powder samples of LaAlO₃. It provides, in principle, a new method for determining elastic and anelastic properties of powder samples with grain sizes down to nanoscale.]]> Tue 26 Feb 2019 14:22:08 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27358 n+1AX_n phases (n≥2) from the chemical characteristics of known phases was developed. The method was used to identify two potential M₃AC₂ phases Ti₃GaC₂ and Ti₃InC₂. After verifying that the n=1 MAX phases in these systems could be synthesised in bulk using a simple pressureless reactive sintering process, the new phases were synthesised using the same method. DFT calculations were used to test the thermodynamic stability of the new phases against the known competing phases within the same ternary systems. Both were found to be stable although Ti₃InC₂ only marginally so. Crystal structure refinements and comparison to other MAX phases revealed a linear increase in the c-axis length as a function of the atomic radius of the A element.]]> Sat 24 Mar 2018 07:39:38 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27729 Sat 24 Mar 2018 07:36:43 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27728 n+1AX_n phases Cr₂GeC and Cr₂GaC were synthesized with high phase-purity directly from Cr₂O₃; Ge or Ga; and C using a single-step carbothermal reduction. X-ray diffraction and scanning electron microscope analysis of the materials shows them to be >99 mol% Cr₂GeC and 92 mol% Cr₂GaC, respectively. Extension to non-Cr systems is briefly demonstrated by applying the method to the synthesis of V₂GeC.]]> Sat 24 Mar 2018 07:36:43 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:43594 Mon 26 Sep 2022 14:37:51 AEST ]]>