54,241 research outputs found
Current-Induced Effective Magnetic Fields in Co/Cu/Co Nanopillars
We present a method to measure the effective field contribution to
spin-transfer-induced interactions between the magnetic layers in a trilayer
nanostructure, which enables spin-current effects to be distinguished from the
usual charge-current-induced magnetic fields. This technique is demonstrated on
submicron Co/Cu/Co nanopillars. The hysteresis loop of one of the magnetic
layers in the trilayer is measured as a function of current while the direction
of magnetization of the other layer is kept fixed, first in one direction and
then in the opposite direction. These measurements show a current-dependent
shift of the hysteresis loop which, based on the symmetry of the magnetic
response, we associate with spin-transfer. The observed loop-shift with applied
current at room temperature is reduced in measurements at 4.2 K. We interprete
these results both in terms of a spin-current dependent effective activation
barrier for magnetization reversal and a spin-current dependent effective
magnetic field. From data at 4.2 K we estimate the magnitude of the
spin-transfer induced effective field to be Oe
cm/A, about a factor of 5 less than the spin-transfer torque.Comment: 6 pages, 4 figure
Decompression-metamorphism of Dabie Complex and rapid tectonic-uplift from deep level of the orogenic belt
The Dabie Complex can be divided into two metamorphic facies belts, granulite facies and amphibolite facies. Growth zoning in the inner segments of garnets is well preserved in the granulite belt. By contrast, garnets in the amphibolite belt have no composition variations in the inner segments, but show growth zoning in the outer segments. This may imply different incipient metamorphic history for the two metamorphic belts. However, both reaction textures and composition trends that reflect the decompression process are commonly in both of the two belts. Pressure decreased about 0.70 and 0.85 GPa for the granulite and the amphibolite belts, respectively, estimated from mineral thermobarometers. The metamorphic P-T paths are characteristic of collision and subduction, implying that the Dabie Complex underwent rapid subsidence and rapid tectonic uplift. Uplift of the ultrahigh pressure eclogites in the region could also be related to the process.published_or_final_versio
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