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The epitaxial growth of the artificial hexagonal GdMnO3 phase was investigated on substrates with hexagonal symmetries. The GdMnO3 thin films grown on Pt(1 1 1)/Al2O3(0 0 0 1) substrates showed a mixed state of a dominant hexagonal phase and small additional orthorhombic phases, which were stable in bulk. In this study, high oxygen partial pressures during film deposition were found to help to fabricate GdMnO3 thin films in the dominant hexagonal phase. Also, the growth behavior of the small additional orthorhombic GdMnO3 phases was studied by X-ray diffraction (XRD) measurements with a synchrotron radiation X-ray source. This study confirmed that even the orthorhombic GdMnO3 phases prefer specific orientations on the substrates with an in-plane hexagonal symmetry. � 2007 Elsevier B.V. All rights reserved.

Fabrication of Co-Pt nanowire arrays with fcc-Co 3 Pt phase was accomplished by DC electrodeposition in anodic aluminum oxide (AAO) nanotemplates. The microstructural and magnetic properties of the nanowires were investigated as a function of the deposition current density (Co concentration). The nanowires possess fcc-Co 3 Pt phases and are ferromagnetic. Their crystallinity and magnetic performance was enhanced after annealing.

We investigated the correlation between the surface roughness and the magnetic properties in electroplated Ni-Fe Permalloy thin films. The Ni-Fe Permalloy thin films electroplated with electrolytes containing a leveling additive showed reduction of coercivity and increase of permeability compared with those prepared with pure inorganic electrolytes. The decrease of the surface roughness resulted in the reduction of coercivity and showed a strong correlation. The improvements in the surface roughness and coercivity caused the initial and incremental permeability increase by 450% and 130%, respectively.

We investigated the changes of the magnetic properties in electroplated Permalloy thin films by a few organic additives added to the plating electrolytes. Under identical electroplating conditions, the crystalline orientations and the surface roughness of the plated thin films were different from those prepared with a pure electrolyte. These property changes reduced the coercivity and increased the magnetoimpedance ratio (MIR) up to 20%.

We investigated the change of magnetic properties of the electroplated Cu/Co alloys and multilayers caused by organic additives and high temperature annealing. When plated with a pure Cu/Co electrolyte, the alloy contained ∼25% of Cu and ∼75% of Co. The alloy was made of hcp-Co, fcc-Co and Cu(1 1 1) and was super-paramagnetic at room temperature. As we add a few organic additives in the plating electrolyte, the hcp-Co of the films disappeared. The organic additives contained in the electrolytes changed paramagnetic Cu/Co multilayers to ferromagnets. High-temperature thermal annealing increased coercivity due to the growth of the Co grains.

We have investigated the effect of organic additives on electroplated nickel-copper thin films. The plating electrolyte utilized mixtures of copper sulfate and nickel sulfamate. The electrolyte contained small volumes of an appropriate organic additive known as an accelerator. By simply adding an additive, we could vary the concentration of copper between 5 and 15%. Thin films of nickel-copper prepared from the electrolyte containing the additive have also shown alteration of crystalline orientations and increase of magnetoresistance from ∼0.55% to ∼1%. This method has advantage of controlling the composition of the co-deposited nickel-copper without changes in deposition conditions and inducing a change in magnetoresistance. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

CoCu thin films were fabricated on a nanocrystalline substrate by DC electrodeposition. It is found that the composition, structure and magnetic properties of the thin films exhibit a strong dependence on the current density and pH values of the bath electrolyte. The effect of annealing as well as the structure–property relation was investigated.

Summary form only given, as follows. Numerical simulation is performed of the two-dimensional plasma with to a view studying the generation of large-scale flows through the short-scale drift-wave turbulence. The electrostatic turbulence is modeled by Hasegawa-Mima equation with or without an external forcing. Both the shift of the frequency and the nonlinear growth rate of the long-wavelength drift wave will be investigated and the comparison will be made with the proposed predator-prey dynamical system. Without the waves, the energy cascades from the smaller scales to the larger ones and accumulates at the largest possible scale. However, the energy cascade is impeded by the presence of the waves whose frequencies are of the same order as the effective vorticity. As a result, under certain conditions, large-scale zonal flows may develop in the neutral fluids. In addition, plasmas have another important scale in the ion gyro-radius, which may keep the energy cascade from reaching the largest scale and help developing the coherent vortices In this poster, detailed analyses will be presented. regarding the formation of the large-scale flows in terms of the various parameters such as the external forcing, the ion gyro-radius, the dissipation and the system size.

We have grown SrTiO3 thin films by rf-sputtering and studied its photoluminescence (PL) property after postannealing treatments. While the as-grown film does not show any PL signal, visible frequency PL emissions are induced by high temperature (T>550 °C) annealing. When subsequent low-T (50 °C) and long term (>8 months) annealing was made, the PL-spectra evolved into another pattern in which four distinct luminescence peaks appear simultaneously at λ=1.8, 2.2, 2.7, and 3.1 eV. We propose that these remarkable room temperature PL effects are due to both metastable and energetically stabilized defect states formed inside the band gap.

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We have studied the effects of an organic additive, saccharine N-propane sulfonate, on the microstructures, magnetic properties, and magnetoimpedance of electroplated Ni-Fe Permalloy thin films. Compared to thin films prepared with a pure inorganic electrolyte, the Ni-Fe Permalloy thin films electroplated with electrolytes containing the additive have different crystalline orientation, grain size, surface roughness, coercivity, permeability, and magnetoimpedance. There is a strong correlation between the observed structural changes and the changes in the magnetic properties, such as in the coercivity and permeability. The changes are also dependent on the structure of the electroplating cells. By using an appropriate plating cell, the coercivity can be reduced from 0.36 to 0.08 Oe. These changes in the magnetic properties result in an increase in the magnetoimpedance by 31%.

We studied the effects of copper doping on the microstructure and magnetic properties of CoPt nanowires fabricated in anodized aluminium oxide (AAO) nanotemplates by electrodeposition. The morphological observation indicates well-formed CoPt and CoPtCu nanowires, while the structural analysis shows that fcc-Co3Pt phase exists prior to annealing and is retained in the doped nanowires, with minor hcp-CoPt phase postannealing. The doping causes shrinkage of the lattice spacing prior to annealing due to the insertion of smaller copper atoms. Compared to the undoped CoPt nanowires, the magnetic measurements reveal significant enhancement in the magnetic properties of the CoPtCu nanowire postannealing, resulting in the more rapid increase in the coercivity with annealing temperature.

The effect of substrates on the microstructure and magnetic properties of electrodeposited Co nanowire arrays in porous anodic aluminum oxide membrane was investigated. It is found that the nanowires possess dominant (002) and (110) textures on the Co-coated nanocrystalline Finemet™ and Au substrates, respectively. Magnetic measurements show that the easy axis of the nanowire arrays switches from perpendicular to the wire axis on Au to parallel to the wire axis on the Co-coated nanocrystalline Finemet™ substrate.