Benefit of inserting a (Cu/Pt) intermixing dual barrier for the blocking temperature distribution of exchange biased Co/(Cu/Pt)/IrMn stacks

Abstract

International audienceExchange bias based spintronics devices involve ferromagnetic/antiferromagnetic interfaces and concomitant layers intermixing. As a consequence, interfacial spin-glass-like phases with reduced properties and increased dispersions form and lower the device performance. It is therefore necessary to limit intermixing by introduction of diffusion barriers. One of the major difficulties is that the barrier must be inert. This paper uses blocking temperature distributions to quantify the interfacial quality of Co/IrMn based stacks. Inserting a (Cu/Pt) dual barrier fulfils the manifold requirements of limiting Co-Mn, Co-Pt, and Cu-Mn intermixing, which takes place when using either no or single Pt and Cu barriers, respectivel

Penetration depth and absorption mechanisms of spin currents in Ir20Mn80 and Fe50Mn50 polycrystalline films by ferromagnetic resonance and spin pumping

“…If the uncompensated spins at the AF interface were fully oriented toward the same direction, we would expect Cu/IrMn spin pumping conductivity (g "# Cu=IrMn /S) similar to Cu/F, typically around 14 to 16 nm À2 . However AF interfaces are known to be highly frustrated, 34,35 and the resulting overall picture gives few uncompensated spins (e.g., tiny F regions) at the AF interface, also responsible for exchange bias. While an AF spin surface in contact with an F is tuned by the interfacial F spin configuration that orients the AF uncompensated spins in a preferential direction after field cooling, in the present case of Cu/AF the AF interfacial uncompensated spins are rather randomly oriented positively and negatively.…”

Enhanced Spin Pumping Efficiency in Antiferromagnetic IrMn Thin Films around the Magnetic Phase Transition

“…2(b). Note that the experimental framework may differ from the ideal theoretical one, since the IrMn structure and the Cu/IrMn interface are altered by species mixing and alloy formation [37]. In addition, the influence on ↑↓ IrMn Cu g / of the non-trivial orientation of the IrMn moments with respect to the interface [38] almost certainly complicates the real picture.…”

Influence of finite-size and edge effects on the exchange-bias properties of ferromagnetic/antiferromagnetic nanodots: Granular Monte Carlo investigation

“…Based on experimental measurements [31,32], disordered interfacial phases extend over 3-4 atomic planes, thus we set t SG = 2 nm. In fact, it was demonstrated experimentally that the fraction of SG x SG may be varied between about 20% and 80%, as it is sensitive to interfaces and concomitant layers intermixing, and that it therefore depends on the stack and fabrication process [33]. For that in our simulations, we fixed the fraction of SG x SG at the interface to an average value of 50% in both nanodots and continuous films.…”