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Unshielded spin-valve sensors (6 X 2 (mu)m(super 2)) with both synthetic ferrimagnet free (SF) and synthetic antiferromagnet pinned (SAF) layers are demonstrated, exhibiting high sensitivities, good thermal stability and reduced free layer effective magnetic thickness. After current biasing, the sensors show a linearized response, demonstrating a coherent switching of the synthetic free layer.

The magnetization orientation of the polarizing reference layer would fluctuate between the parallel and antiparallel states when the reference layer loses stability. In this paper, a combined analytical and simulation study is presented to predict the magnetic dynamics of the spin valve element with single-domain magnets as the free and reference layers. We acquire a complete phase diagram that includes the normal spin-torque switching and random magnetization fluctuations by tuning the spin torque strength between the free and reference layers. The phase dynamics strongly depends on the magnetization state of the reference layer, showing that the instability of the reference layer could be responsible for the random fluctuation events. [ABSTRACT FROM AUTHOR]

The magnetic domain configuration and the magnetization reversal behavior of micropatterned exchange bias elements were investigated by means of magnetic force microscopy. In addition to the unidirectional anisotropy the shape anisotropy determines the overall magnetization reversal behavior. In order to modify the ratio between both anisotropy contributions, the exchange bias field strength was reduced by means of 5 keV He+ ion irradiation. For the as-prepared samples, a monodomain magnetization state with the magnetization direction aligned along the exchange bias field direction was found regardless of the element shape. After irradiation the unidirectional anisotropy contribution is reduced and hence the previously homogeneous magnetization state breaks up into small domains with 360° domain walls in between. The appearance of these domain walls, which was mainly observed for the descending branch of the magnetization reversal, is found to depend strongly on the structure width and orientation. [ABSTRACT FROM AUTHOR]

The exchange-biased Permalloy planar Hall effect sensor crosses is examined. The studies have shown that a single domain model has described the system well and that the thicker film will have a higher signal as well as a lower noise and also the signal-to-noise ratio for bead detection has increased by a factor 2.1.

The radiation of spin waves by rectangular spin-valve elements into a surrounding magnetic film is studied experimentally. It is found that the elements radiate spin waves at frequencies corresponding to their laterally quantized spin-wave eigenmodes.