Magnetic field modulation of intense surface plasmon polaritons

We present correlated experimental and theoretical studies on the magnetic field modulation of Surface Plasmon Polaritons (SPPs) in Au/Co/Au trilayers. The trilayers were grown by sputter deposition on glass slides with the Co films placed at different distances from the surface and with different thickness. We show that it is possible to tailor Au/Co/Au trilayers with the critical thickness needed for optimum excitation of SPPs leading to large localized electromagnetic fields. The modification of the SPP wave vector by externally applied magnetic fields was investigated by measuring the magneto-optical activity in transverse configuration. In addition, using magneto-optics as a tool we determined the spatial distribution of the SPP generated electromagnetic fields within Au/Co/Au samples by analyzing the field-dependent optical response, demonstrating that it is possible to excite SPPs that exhibit large electromagnetic fields that are also magneto-optically active and therefore can be modulated by externally applied magnetic fields. (C)2010 Optical Society of Americ

Order and phase nucleation in nonequilibrium nanocomposite Fe-Pt thin films with perpendicular magnetic anisotropy

We report on the time evolution of mass transport upon annealing nonequilibrium Fe-Pt nanocomposite films, leading to nucleation of L1(0) chemically ordered phase. The nonequilibrium nanocomposite films were fabricated by applying Fe(+) ion implantation to epitaxial Pt films grown on (001) MgO substrates, yielding Fe nanoclusters embedded in a Pt matrix at a tailored penetration depth. Time-resolved x-ray diffraction studies were carried out using synchrotron radiation, allowing determination of the activation energy for nucleation of the FePt L1(0) phase within the segregated nanoclusters during annealing. The growth of the segregated L1(0) ordered phase was modeled using ideal grain-size law and found to be dominated by strain-driven surface nucleation. The activation energies were found to correlate with the nanocluster size. Magnetic characterization of selected annealed samples indicates perpendicular magnetic anisotropy with high coercive field coincident with high value of the chemical order parameter of the ordered phase within the magnetic nanoclusters

Control of the perpendicular magnetic anisotropy of FePd films via Pd capping deposition

We have investigated the influence of two capping layers (MgO and Pd) on the magnetic anisotropy of highly anisotropic L10 FePd films. While we mainly found perpendicular magnetic anisotropy in MgO capped films, we observed that the Pd capping layer induces formation of an additional new phase near the FePd/Pd interface that exhibits in-plane magnetic anisotropy. The combined effect of these two anisotropies results in global canted magnetic anisotropy. Thus, our findings illustrate a mechanism to influence the magnetic anisotropy in FePd highly ordered alloys via adequate choice of capping layer materials.Peer reviewe

Optimizing the planar structure of (1 1 1) Au/Co/Au trilayers

Au/Co/Au trilayers are interesting for a range of applications which exploit their unusual optical and electronic transport behaviour in a magnetic field. Here we present a comprehensive structural and morphological study of a series of trilayers with 0–7 nm Co layer thickness fabricated on glass by ultrahigh vacuum vapour deposition. We use a combination of in situ electron diffraction, atomic force microscopy and x-ray scattering to determine the optimum deposition conditions for highly textured, flat and continuous layered structures. The 16 nm Au-on-glass buffer layer, deposited at ambient temperature, is found to develop a smooth (1 1 1) texture on annealing at 350 °C for 10 min. Subsequent growth of the Co layer at 150 °C produces a (1 1 1) textured film with lateral grain size of ∼150 nm in the 7 nm-thick Co layer. A simultaneous in-plane and out-of-plane Co lattice expansion is observed for the thinnest Co layers, converging to bulk values for the thickest films. The roughness of the Co layer is similar to that of the Au buffer layer, indicative of conformal growth. The 6 nm Au capping layer smoothens the trilayer surface, resulting in a surface roughness independent of the Co layer thickness.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58140/2/d7_9_003.pd

Niobium thin film deposition studies on copper surfaces for superconducting radio frequency cavity applications

Thin film coatings have the potential to increase both the thermal efficiency and accelerating gradient in superconducting radio frequency accelerator cavities. However, before this potential can be realized, systematic studies on structure-property correlations in these thin films need to be carried out since the reduced geometry, combined with specific growth parameters, can modify the physical properties of the materials when compared to their bulk form. Here, we present our systematic studies of Nb thin films deposited onto Cu surfaces to clarify possible reasons for the limited success that this process exhibited in previous attempts. We compare these films with Nb grown on other surfaces. In particular, we study the crystal structure and surface morphology and their effect on superconducting properties, such as critical temperature and lower critical field. We found that higher deposition temperature leads to a sharper critical temperature transition, but also to increased roughness indicating that there are competing mechanisms that must be considered for further optimization

Marine Monitoring Program: Annual report for inshore water quality monitoring 2014-2015

[Extract] The management of water quality remains an essential requirement to ensure the long-term protection of the coastal and inshore ecosystems of the Great Barrier Reef (GBR) (Commonwealth of Australia, 2015). The land management initiatives under the Australian and Queensland Government's Reef Water Quality Protection Plan (Reef Plan) and the Reef 2050 Long Term Sustainability Plan (Reef 2050 Plan) are key actions to improve the water quality entering the GBR. The goal of Reef Plan is “To ensure that by 2020 the quality of water entering the reef from broadscale land use has no detrimental impact on the health and resilience of the Great Barrier Reef.” This report summarises the results of water quality monitoring activities, carried out by the Australian Institute of Marine Science (AIMS) and James Cook University (JCU) as part of the Marine Monitoring Program (MMP) in 2014-15, with reference to previous data from 2005 to 2014

Marine Monitoring Program: Annual report for inshore water quality monitoring 2018-19

[Extract] The program design includes the collection of water samples along transects in the Cape York, Wet Tropics, Burdekin and Mackay-Whitsunday regions year-round, with higher frequency sampling during the wet season to better characterise this period of episodic river discharge. Satellite imagery and modelling simulations are linked with in-situ monitoring data to estimate the exposure of inshore areas to end-of-catchment loads from rivers