Jan-ulrich Thiele

Amorphous hydrocarbon layers (a-C:H) prepared by plasma assisted chemical vapor deposition (PECVD) were investigated with respect to their possible semiconducting properties. Cluster calculations were performed to confirm that a true band gap may be formed in these ...

Here, we will present FETD modeling results which optimize peak power absorption in the disk media. We have used plane-wave illumination (which can approximate the wavefront from a laser cavity or thin-film waveguide). The aperture and slider material are assumed to be quartz. We have found globally optimized ridge waveguide designs as a function of wavelength and fly-height. For optimized structures, we do find clear resonant behavior in the near field pattern although the resulting near-field "spectra" bear little resemblance to the calculated far field transmission spectra. That is, high far-field transmission does not indicate a good design for data recording. We will also present modeling results on the effects of fly-height variation for fixed design, how dielectric overcoats influence ridge waveguide efficiency, and the effects of media thickness and the presence of a heatsink. Results for various metals will be shown.

ABSTRACT For [Co(3 angstrom)/Pt(10 angstrom)]n multilayers and FePt(111) L10 ordered films exposed to energetic ion beam irradiation, we have experimentally determined the dependence of the perpendicular coercivity on ion dose, for a variety of ion species and energies. A simple model based on ballistic displacement of Co (or Fe) atoms from ordered configurations is presented, which predicts an exponential decline of anisotropy with ion dose. The perpendicular coercivity for these samples is indeed found to decline in this way. The ballistic displacement model, evaluated using SRIM Monte Carlo simulation, roughly reflects the observed dependence on ion species and energy. However, the experimental data would demand a displacement probability per incident ion many times larger than that obtained from SRIM.

An overview of media properties and their influence on the recording process in thermally assisted magnetic recording (TAR) will be given. A novel media scheme using exchange coupled FePt/FeRh bi-layers that attempts to circumvent some of the limitations encountered by 'simple' ferromagnetic media will be discussed. Utilizing the exchange spring behavior of the bi-layer above TAF-FM, this concept allows reversal

... 4, 741 (2005). M. Hayashi, L. Thomas, C. Rettner, R. Moriya, and SSP Parkin, Nat. Phys. 3, 21 (2007). M. Hayashi, L. Thomas, C. Rettner, R. Moriya, and SSP Parkin, Appl. Phys. Lett. ... 4, 741 Í 2005Í . 13 M. Hayashi, L. Thomas, C. Rettner, R. Moriya, and SSP Parkin, Nat. Phys. ...