Ferromagnetic resonance study of dual exchange bias field behavior in NiFe/IrMn/Co trilayers

Abstract

Magnetometry study of magnetron sputtered NiFe/IrMn/Co trilayers reveal that the exchange bias field at the NiFe/IrMn interface decreases with increasing NiFe layer thickness, up to 150 Å. At the IrMn/Co interface, a decrease also occurs when the NiFe layer thickness increases. Ferromagnetic resonance measurements at X and Q-band frequencies reveal that the same dependence at both interfaces, up to a 70 Å thick NiFe, is due to a spiraling interlayer coupling between the NiFe and Co layers. Unexpected increase with thicker NiFe layer is due to domain walls at the NiFe/IrMn interface in the presence of low static magnetic fields.

Dual mode spin to charge conversion using inverse spin Hall effect in NiFe/FeMn/NiFe multilayer thin films

“…Hence, the bottom and top interfaces of the FeMn layer will exhibit different spin configurations. Secondly, due to the variation of microstructure in the FeMn layer, the strength of exchange coupling for two FM layers will be different at the bottom and top NiFe/FeMn interfaces [10,27]. This leads to the conclusion that a higher EB shift was observed for the bottom NiFe layer, and the results are consistent with those of earlier works [25,28].…”

“…In this context, a novel trilayer structure consists of two ferromagnetic (FM) layers separated by an antiferromagnetic (AFM) layer, i.e. FM/AFM/FM can be a potential candidate for such application [10][11][12]. In these stacks, the AFM layer plays a key role by pinning the adjacent FM layers via the exchange bias (EB) effect and essentially shifts the hysteresis loop due to the increment in the switching field of FM layers [13,14].…”

Exchange bias in FeNi/FeMn/FeNi multilayers

“…However, their results did imply a coupling of exchange interaction between two EB systems [22,30]. Some studies suggest that this interaction is quite short and does not exceed the thickness of the domain wall in the antiferromagnet [21,23,32,34]. At the large AF layer thicknesses, this interaction is almost imperceptible, and EB systems behave independently [32].…”

Probing the Transfer of the Exchange Bias Effect by Polarized Neutron Reflectometry

“…On the other hand, AF ordered spins in the bulk of the AF layer are also considered to be very important for the EB effect 5–9 . To fully understand the significance of the AF spin structure a FM/AF/FM trilayer has become an ideal structure for investigations 8,10–16 . 90° interlayer exchange coupling between the FM layers has been found through a metallic AF layer, such as Mn 17 and Cr 18 , and even through an insulating AF layer, such as NiO 19,20 .…”