Focused ion beam fabrication of spintronic nanostructures: an optimization of the milling process.

Focused ion beam (FIB) milling has been used to fabricate magnetic nanostructures (wires, squares, discs) from single magnetic layers (Co, permalloy) and spin-valve (permalloy/Cu/Co) multilayers (thicknesses 5-50 nm) prepared by ion beam sputtering deposition. Milled surfaces of metallic thin films typically exhibit residual roughness, which is also transferred onto the edges of the milled patterns. This can lead to domain wall pinning and influence the magnetization behaviour of the nanostructures. We have investigated the milling process and the influence of the FIB parameters (incidence angle, dwell time, overlap and ion beam current) on the roughness of the milled surface. It has been found that the main reasons for increased roughness are different sputter yields for various crystallographic orientations of the grains in polycrystalline magnetic thin films. We have found that the oblique ion beam angle, long dwell time and overlap < 1 are favourable parameters for suppression of this intrinsic roughness. Finally, we have shown how to determine the ion dose necessary to mill through the whole thin film up to the silicon substrate from scanning electron microscopy (SEM) images only.

[Side effects of oral contraceptives in the first treatment cycle]. / Nebenwirkungen oraler Kontrazeptiva im ersten Einnahmezyklus.

In order to compare the secondary effects of oral contraceptive pills during the first cycle of application, 308 women between the age of 25 and 45 were interrogated by questionnaires about their subjective complaints. The patients received a contraceptive within an In-vitro-Fertilization-program (IVF-program) in preparation for a stimulation treatment to follow. The study consisted of two parts: at the beginning a pilot study was carried out in which retrospectively a pill containing 0.150 mg Desogestrel and 0.030 mg Ethinylestradiol and a contraceptive containing 0.075 mg Gestoden and 0.030 mg Ethinylestradiol were compared. In a following prospective randomized examination a product, new on the market, containing 0.250 mg Norgestimat and 0.035 mg Ethinylestradiol, was included. The most common secondary effects, occurring in 34% of our patients, were spottings and break through bleedings. Regarding the secondary effects--during the first cycle of application--no significant difference between the contraceptives could be established.