Switching field interval of the sensitive magnetic layer in exchange-biased spin valves

Abstract

The switching field interval, ⌬H s , of Ni-Fe-Co-based thin films and spin-valve layered structures, sputter-deposited on a Ta-buffer layer, was studied. The switching field interval is the field range in which the magnetization reversal of a ferromagnetic layer takes place. In thin films, ⌬H s is determined by the uniaxial anisotropy, induced by growth in a magnetic field. This anisotropy increases with the ferromagnetic layer thickness and saturates at a thickness of 10-25 nm. It also depends on the alloy composition as well as on the choice of the adjacent layers. In exchange-biased spin valves, an additional contribution to ⌬H s was observed, which increases monotonically with increasing interlayer coupling. We explain this in terms of the effect on the magnetization reversal of the sensitive layer due to a simultaneous small, but temporary, magnetization rotation in the exchange-biased layer and lateral variations of the interlayer coupling. In addition, the effect of biquadratic coupling on ⌬H s is discussed. Finally, the thermal stability of ⌬H s is investigated.

Magnetization Manipulation of a Flexible Magnetic Sensor by Controlled Stress Application

“…4(c) layers (See Figs S2 and S3 in Supporting Information). The sensitivity, which is defined as the value of MR ratio divided by the switching field interval, which can be expressed as 2 H k 40 , also increases monotonically from 0.103%/Oe in the after-flat-state for 5-times bending to 0.138%/Oe in the after-flat-state for 100-times bending because the MR ratio increases rapidly, despite 2 H k also increasing.…”

Anisotropy in magnetic materials for sensors and actuators in soft robotic systems

“…R AP and R P represent the resistances for the antiparallel and parallel states, respectively. The field sensitivity of a GMR sensor is calculated as follows: 231 where H op is the operation field. Eqn (20) indicates that the field sensitivity relying on the GMR effect greatly increases with a significant change in resistance changes over a very narrow range of the external magnetic field.…”