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Scanning probe microscopy resist patterning was proposed for the fabrication of nanometer-scale thin carbon layers. Unlike conventional resist processing, which requires solvent resist elimination, the proposed approach involves direct nano-scaled pattern writing. Results indicate that local field-induced oxidation of the carbon layer beneath the tip causes trench formation.

Giant magnetoresistance (GMR) measurements for Co/Cu multilayered thin films during their growth facilitate the characterization of their electron transport and layer formation. The newly developed in situ magnetoresistance measurement technique identifies the correlation between the growth mechanism and GMR as a function of Co thickness, effectively. Mean free paths of electron transport and interface scattering determine the magnitude of GMR effect.

Ultrahigh vacuum scanning-tunneling-microscopy study of large mass movement in current carrying metallic films shows that local inhomogeneities of the electric field exist in thin films. The current carrying capacity of these films decrease at certain ranges of current densities as there is a runaway thermal fusing mechanism. Topographical changes such as current aligned grain growth, current induced faceting and complex mass flow divergences are also observed.

We investigate the frequency of thermally excited vortex oscillations in Co-Fe-B magnetic tunnel junction (MTJ) pillars in the presence of defects. Under a variable in-plane magnetic field, a characteristic behavior is observed: the frequency oscillates from a maximum at certain field values to a steep minimum, which tends towards zero frequency. These frequency variations are described qualitatively well by an analytical model based on the Thiele equation taking into account a single Gaussian pinning potential. It is thus possible to calculate the in-plane depinning field for certain pinning potential parameters. For steep potentials, the depinning is hysteretic and jumps between the pinned and unpinned regime occur due to the presence of an energy barrier. A sharp frequency minimum occurs at an applied field, where a large flat region in the energy landscape is present. From the experiments, the pinning potentials are estimated to be between -0.2eV and -0.4eV. We also perform micromagnetic simulations of the vortex oscillations in the presence of a distribution of pinning centers. The simulations confirm the validity of the Thiele-approach showing that the vortex remains sufficiently rigid. [ABSTRACT FROM AUTHOR]

We fabricated NiFe2O4 thin films on MgAl2O4 (001) substrates by reactive dc magnetron co-sputtering in a pure oxygen atmosphere at different substrate temperatures. The film properties were investigated by various techniques with a focus on their structure, surface topography, magnetic characteristics, and transport properties. Structural analysis revealed a good crystallization with epitaxial growth and low roughness and a similar quality as in films grown by pulsed laser deposition. Electrical conductivity measurements showed high room temperature resistivity (12Ωm), but low activation energy, indicating an extrinsic transport mechanism. A band gap of about 1.55 eV was found by optical spectroscopy. Detailed x-ray spectroscopy studies confirmed the samples to be ferrimagnetic with fully compensated Fe moments. By comparison with multiplet calculations of the spectra, we found that the cation valencies are to a large extent Ni2+ and Fe3+. [ABSTRACT FROM AUTHOR]

The signal response of Bangs Laboratories magnetic markers with a mean diameter of 0.86 [micro]m on a spiral-shaped giant magnetoresistance sensor with a diameter of 70 [micro]m is investigated. The data show a linear dependence of the sensor signal on the surface coverage of the magnetic markers. The detection limit is reached at a coverage of about 5%, which corresponds to about 200 markers distributed across the surface of the sensor. The corresponding molecular binding of the analyte DNA and the magnetic markers show good selectivity and sensitivity. Index Terms--Biomagnetics, biomedical measurements, magnetoresistive devices, sensors.

Co nanocrystals have been prepared via two different chemical preparation routes. Microstructural characterization has been carried out by conventional and high-resolution transmission electron microscopy. Magnetic characterization reveals that Co nanocrystais with mean particle size distributions about 6 nm are ferromagnetic at room temperature. Superlattices of about 1 [micro]m x 1 [micro]m can be reproduced. For the second preparation route the formation of an [epsilon]-Co phase was detected by X-ray diffraction. Whereas the pure Co nanocrystals form domains with a mixture of simple cubic and hexagonal packing, FeCo alloyed nanoparticles form long chain-like structures. Index Terms--Arrays, electron microscopy, magnetic materials, nanocluster, superlattices.

The magnetic field generated by a current on chip at the location of the spin dependent tunneling (SDT) element is calculated depending on the geometric parameters of the current line and for the critical current density. No magnetic stability of the Ru/CoFe hard magnetic layer based tunneling system was measured during unidirectional switching.