https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:48318 Tue 14 Mar 2023 15:37:36 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:45389 2O₃ films were deposited using a pulsed laser deposition system. X-ray diffraction and transmission electron microscopy analysis show that the films deposited under oxygen partial pressures of 10^–3 and 10^–5 Torr are uniform without clusters or secondary phases. However, the film deposited under 10^–7 Torr has a Fe-rich phase at the interface. Magnetic measurements demonstrate that the magnetization of the films increases with decreasing oxygen partial pressure. Muon spin relaxation (μSR) analysis indicates that the volume fractions of the ferromagnetic phases in PO₂ = 10^–3, 10^–5, and 10^–7 Torr-deposited samples are 23, 49, and 68%, respectively, suggesting that clusters or secondary phases may not be the origin of the ferromagnetism and that the ferromagnetism is not carrier-mediated. We propose that the formation of magnetic bound polarons is the origin of the ferromagnetism. In addition, both μSR and polarized neutron scattering demonstrate that the Fe-rich phase at the interface has a lower magnetization compared to the uniformly distributed phases.]]> Tue 08 Nov 2022 09:39:02 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:54120 -1 at 0.5 A g^-1 ), large specific capacity for sodium-ion battery (349 mAg h^-1 at 50 mAh g^-1 ), and excellent CO₂ adsorption capacity (27.14 mmol g^-1 at 30 bar). Density functional theory calculations demonstrate that different adsorption sites (B-C, B-N, C-N, and C-C) and the large specific surface area strongly support the high adsorption capacity. This finding offers an innovative breakthrough in the design and development of MBCN nanostructures for energy storage and carbon capture applications.]]> Tue 06 Feb 2024 11:29:36 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:52445 4+/Ce³⁺ compositions. Using DFT calculations combined with Bader charge analysis, it is demonstrated that stoichiometric ceria registers a higher oxidase mimetic activity than oxygen-deficient ceria with a low Ce⁴⁺/Ce³⁺ ratio due to a higher charge transfer from a substrate, 3,3',5,5' tetramethylbenzidine (TMB), to the ceria surface. We also show that the fluoride ions can significantly increase the charge transfer from the TMB surface to ceria irrespective of the surface Ce⁴⁺/Ce³⁺ ratio. Using this knowledge, we first compare the fluoride sensing properties of nanoceria with high Ce⁴⁺ and mixed Ce⁴⁺/Ce³⁺ oxidation states and further demonstrate that the linear detection range of fluoride ions can be extended to 1-10 ppm for nanoceria with mixed oxidation states. Then, we also demonstrate an assay for fluoride assisted detection of glutathione, an antioxidant with elevated levels during cancer, using nanoceria with a high surface Ce⁴⁺/Ce³⁺ ratio. The addition of fluoride ions in this assay allows the detection of glutathione in the linear range of 2.5-50 ppm with a limit of detection (LOD) of 3.8 ppm. These studies not only underpin the role of the surface Ce⁴⁺/Ce³⁺ ratio in tuning the fluoride assisted boost in the oxidase mimetic activity of nanoceria but also its strategic application in designing better colourimetric assays.]]> Thu 12 Oct 2023 15:28:04 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:53883 Mon 22 Jan 2024 12:50:50 AEDT ]]>