ABSTRACT
We propose a system allowing the characterization of thin magnetic multilayer structures that combine conversion electron Mossbauer spectrometry (CEMS) under applied magnetic field with the magneto-optical Kerr effect (MOKE) technique. Measured hysteresis loops obtained from the MOKE part are used for investigation of sample surface magnetic properties. The CEMS part of such a system is suitable for studying the spatial spin distribution during magnetization reversal under applied magnetic field, whose values are established from the measured MOKE loop. The combined technique is demonstrated on the results obtained at 300 K on an exchange-coupled ferrimagnetic amorphous GdFe/TbFe bilayer, where the center of the GdFe layer is enriched in (57)Fe. Both techniques confirm in-plane uniaxial anisotropy. The spin structure at the position of the probe layer is analyzed for several values of the external magnetic field applied in the hard magnetization axis direction.
ABSTRACT
The structural and magnetic properties of the evaporated Fe/V multilayers with a fixed V-layer thickness (tV = 1.5 nm) and variable Fe layer thicknesses (0.75 nm < or = tFe < or = 6 nm) have been studied by X-ray reflectivity and high-angle X-ray diffraction, conversion-electron Mössbauer spectrometry, and vibrating sample magnetometry. The results show that multilayers are formed with a broad Fe/V interface and pure crystalline bcc-Fe layers in the center of the individual subsystems. The Fe spin orientation is aligned in the film plane in the individual centers as well in the interfacial regions. The interfacial anisotropy constant Ks was estimated to be equal to 0.04 mJ/m2. This parallel magnetic anisotropy is discussed in terms of reduced symmetry effects on the hybridized 3d states.
Subject(s)
Crystallization/methods , Iron/chemistry , Materials Testing/methods , Nanotechnology/methods , Vanadium/chemistry , Anisotropy , Electromagnetic Phenomena/methods , Gases/chemistry , Hot Temperature , Magnetics , Molecular Conformation , Spectroscopy, Mossbauer , Structure-Activity Relationship , Surface Properties , Temperature , X-Ray DiffractionABSTRACT
The delivery of 71 African women who had been circumcised was studied against a control of 781 women who were not circumcised. We have not been able to find any difference as far as caesarean section, forceps delivery or fetal distress in the two groups that were studied. The only difference is a higher frequency of perineal injury in the group of circumcised women.
Subject(s)
Circumcision, Male/adverse effects , Obstetric Labor Complications/etiology , Cote d'Ivoire , Democratic Republic of the Congo , Female , Humans , Mali , Mauritania , Pregnancy , SenegalABSTRACT
One hundred and thirty-eight femoral lengthening operations have been performed in 133 children. The etiology of the shortening was poliomyelitis in 71, infection in 20 and congenital abnormalities in 28. The femur was lengthened in one operative stage by step-cut osteotomy, immediate traction and plate fixation. The mean gain was 35 mm with a maximum of 55 mm. The range of knee movement was unaffected except in 6 cases. Infection occurred in 2 patients without prejudicing the final result. Bony union was obtained in all cases, bone grafting being necessary only once. One permanent sciatic palsy was seen. Thirteen fractures occurred in 9 femurs. Two occurred during operation with loss of lengthening in one case. Eleven occurred post-operatively at the site of osteotomy. One case fractured on 3 occasions. Two cases fractured in another portion of the femur. The complications became fewer with experience and with more accurate technique and it is concluded that the method is safer than progressive lengthening at least in moderate limb length discrepancy.
