The influence of ultrathin Cu interlayer in NiFe/IrMn interface on rotation of the magnetic moments

A comprehensive study for influence of NiFe(10 nm)/IrMn(4 nm) with Cu inserted on magnetization process of magnetic moments with Planar Hall effect (PHE) method has been demonstrated in this letter. For the samples without Cu space layer, the exchange bias field about 62 Oe is completely enough to provide unidirectional pinning direction for the rotation of magnetic moments in ferromagnetic layer. However, the rotation of magnetic moments is not coherent and the hysteresis is about 5 Oe. As to the sample with Cu inserted, although the exchange coupling is declined and the pinning strength is very weak, the rotation of magnetic moments is coherent and the hysteresis is about 0.8 Oe. The magnetization rotation strongly depends on the change in states of pinning direction before and after the ultrathin Cu layer being inserted at NiFe/IrMn interfaces.