Perpendicular magnetoresistance of microstructured pillars in Fe/Cr magnetic multilayers

\u3cp\u3eWe have fabricated pillar-like microstructures of high vacuum sputtered Fe/Cr magnetic multilayers and measured the giant magnetoresistance effect in the configuration where the measuring current is perpendicular to the film plane from 4.2 K to 300 K. At 4. 2 K we find a magnetoresistance of 108 % for multilayers with a Fe thickness of 3 nm and a Cr thickness of 1 nm. The pronounced temperature dependence of the perpendicular magnetoresistance is studied for samples with different Cr thicknesses and tentatively explained by electron-magnon scattering. The low-temperature data are compared with existing low-temperature models.\u3c/p\u3

Depletion-type thin-film transistors with a ferroelectric insulator

We present a study of electrical characteristics of ferroelectric field-effect transistors made of PbZr0.2Ti0.8O3 and SnO2:Sb thin films. Due to properly chosen semiconductor parameters, the transistor channel can be totally depleted by the ferroelectric charge displacement. The observed remnant on/off ratio of the channel current amounts to 7×103. Pulse response measurements give information on data retention, device speed, and the occurrence of charge injection. The results lead to important design considerations for ferroelectric transistors

X-ray examination apparatus

The invention relates to an X-ray apparatus which includes an adjustable X-ray filter. In order to adjust an intensity profile of the X-ray beam, an X-ray absorbing liquid is transported to filter elements of the X-ray filter. Such transport is susceptible to gravitational forces which lead to an irregular hydrostatic pressure distribution in the X-ray filter. In order to reduce the effects of the gravitational forces on the transport of the X-ray absorbing liquid, the duct connecting the filter elements to the reservoir is subdivided into sub-ducts and the reservoir is subdivided into chambers, each chamber being connected to at least one sub-duct. The X-ray apparatus also includes means for keeping the sub-ducts aligned with a horizontal plane. [on SciFinder (R)

1/f Noise in magnetic Ni80Fe20 single layers and Ni80Fe20/Cu multilayers

We have investigated the room temperature 1/f noise of microstructured soft magnetic Ni80Fe20 films, showing the anisotropic magnetoresistance effect, and of Ni80Fe20/Cu magnetic multilayers, showing the giant magnetoresistance effect. We find that the 1/f noise in magnetic multilayers is considerably enhanced with respect to the noise of the single domain layer and attribute this to the complex domain structure of the multilayer

Interpretation of the giant magnetoresistance effect in Co/Cu(100) multilayers with the quantum model of giant magnetoresistance

\u3cp\u3eWe have measured the magnetoresistance of high-vacuum-sputtered Co/Cu(100) multilayers grown on Cu buffer layers. The magnetoresistance in the first antiferromagnetic- (AF-) coupling peak is very sensitive to the buffer layer thickness. We find a linear dependence between the actual measured magnetoresistance and the fraction of AF coupling, as determined by magnetization measurements. We compare our Co/Cu(100) magnetoresistance data at 4 K of completely antiparallel-aligned multilayers with the quantum model of giant magnetoresistance of Levy, Zhang, and Fert. This reveals evidence for strong spin-dependent interface scattering, whereas the spin dependence of the bulk scattering in Co is small.\u3c/p\u3

Determination of spin-dependent scattering parameters of NiFe/Cu and Co/Cu multilayers

We present magnetoresistance (MR) data of high-vacuum magnetron sputtered NiFe/Cu multilayers (NiFe=NisoFe20) grown on Si(lOO) substrates with a Cu buffer layer and compare these with earlier results on Co/Cu(lOO) multilayers [1]. Measured MR values are directly proportional to the antiferromagnetically coupled fraction in the multilayers. Extrapolating to full antiparallel alignment, we can make a reliable comparison of the MR wrt,h the magnetoresistance model of Levy,\u3cbr/\u3eZhang, and Fert [2,3]. For the NiFe/Cu multilayers the deduced spin-asymmetry parameters are a~iFe/Cu = 5.0 ± 0.4 and a~iFe = 2.1 ± 0.3 for interface and bulk scattering, respectively. Although much smaller than in our Co/Cu multilayers, where afo/Cu = 21 ± 3 and af0 = 2.6 ± 0.3, .it is still the spin dependence of the interface scattering that is the main cause for the large MR values