English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Antiferromagnetic spintronic devices have the potential to outperformconventional ferromagnetic devices due to their ultrafast dynamics and highdata density. A challenge in designing these devices is the control anddetection of the orientation of the anti-ferromagnet. One of the most promisingways to achieve this is through the exchange bias effect. This is of particularimportance in large scale multigranular devices. Due to the large system sizes,previously, only micromagnetic simulations have been possible, these have anassumed distribution of antiferromagnetic anisotropy directions. Here, we usean atomistic model where the distribution of antiferromagnetic anisotropydirections occurs naturally and the exchange bias occurs due to the intrinsicdisorder in the antiferromagnet. We perform large scale simulations, generatingrealistic values of exchange bias. We find a strong temperature dependance ofthe exchange bias, which approaches zero at the blocking temperature while thecoercivity has a peak at the blocking temeprature due to the superparamagneticflipping of the antiferromagnet during the hysteresis loop. We find a largediscrepancy between the exchange bias predicted from a geometric model of theantiferromagnetic interface indicating the importance of grain edge effects inmultigranular exchange biased systems. The grain size dependence shows theexpected peak due to a competition between the superparamagnetic nature ofsmall grains and reduction in the statistical imbalance in the number ofinterfacial spins for larger grain sizes. Our simulations confirm the existenceof single antiferromagnetic domains within each grain. The model gives insightsinto the physical origin of exchange bias and provides a route to developingoptimised nanoscale antiferromagnetic spintronic devices.

The origin of exchange bias in multigranular non-collinear IrMn$_3$/CoFe thin films