Altering the bias direction during the process of field-cooling can result in variations of non-collinear directions (helicities), which influence the number of irreversible spins and the resulting exchange coupling differently depending on the direction of the bias. The statistical differences in spin configuration \(\delta m_{r}^{{ + / - }}\) , along with the corresponding exchange bias field \(H_{{eb}}^{{ - / + }}\) values, are utilized to study the changes as a function of temperature within an antiferro-ferro(magnetic)–rare-earth (AF–FM–RE) system (Mn3Ir/CoFe/Dy). We examine two samples, one featuring a thinner FM layer compared to another with a thicker FM layer, reported earlier. We demonstrate how diverse field-cooling methods, stemming from slight statistical discrepancies in irreversible spins, significantly impact the magnitudes while preserving their overall characteristics. Even with a reduction in the thickness of the FM layer, there was no indication of spin-freezing or blocking-type ordering in the system, apart from the observation of ferromagnetic characteristics with temperature-shifted magnetic phases. Deterioration of the FM–RE interface has resulted in a lowering of \(\delta m_{r}^{{ + / - }}\) contribution.
Graphical abstract
