Permalloy multilayers to reduce the effects of uniaxial anisotropy

The anisotropic magnetoresistance effect of Permalloy (Ni0.82 Fe0.18) is used in a contactless angle detector. The uniaxial magnetic anisotropy in a Permalloy thin film causes a difference between the direction of magnetization and the magnetic field direction. This leads to a systematic error in the angle detector output. The effects of uniaxial magnetic anisotropy can be reduced by using Permalloy multilayers with different orientations of their anisotropy axes. A double layer with mutually perpendicular anisotropy axes is found to be sufficient for application in an angle detector. The Stoner-Wohlfarth single-domain model is used to describe the systematic error of an angle detector using multilayer

Development of Spintronic Materials by Stoichiometric Engineering of CoFeVAl

We have carried out an experimental investigation of the Heusler Alloy CoFeVAl and its two variants Co1.5Fe0.5VAl and CoFeVAl0.5Si0.5 for their potential application in the field of spintronics. Heusler alloys are investigated for their many remarkable properties, including half-metallicity and spin-gapless semi-conductivity. Spintronic technology utilizes the intrinsic spin of an electron for information storage and manipulation in solid state devices. We synthesized these alloys using arc-melting and annealing. All three alloys were found to have cubic crystal structures with varying disorders. The parent alloy CoFeVAl shows a magnetic transition at 65 K. However, after modifying the elemental composition by either replacing 50% of Al with Si or the same amount of Fe with Co the magnetic properties substantially changed. The ferromagnetic to paramagnetic transition temperature increased to 215 K. The doped alloys Co1.5Fe0.5VAl and CoFeVAl0.5Si0.5 show saturation magnetizations of 37 emu/g and 35 emu/g, respectively at 100 K

A thin-film magnetoresistive angle detector

An overview is given of the results of our research on a contactless angle detector based on the anisotropic magnetoresistance effect (AMR effect) in a permalloy thin film. The results of high-temperature annealing treatment of the pemalloy film are discussed. Such a treatment suppresses the effects of the uniaxial magnetic anisotropy that is present in a permalloy thin film and increases the AMR effect, thus improving the detector signal. The performance of the detector throughout a temperature range of 20 to 120 °C and the results of heat treatment at 125 °C for 1 week have been tested

International epidemiology of intracerebral hemorrhage

Intracerebral hemorrhage is the second most common subtype of stroke. In recent decades our understanding of intracerebral hemorrhage has improved. New risk factors have been identified; more knowledge has been obtained on previously known risk factors; and new imaging techniques allow for in vivo assessment of preclinical markers of intracerebral hemorrhage. In this review the latest developments in research on intracerebral hemorrhage are highlighted from an epidemiologic point of view. Special focus is on frequency, etiologic factors and pre-clinical markers of intracerebral hemorrhage