Positive exchange-bias and giant vertical hysteretic shift in La0.3Sr0.7FeO3/SrRuO3 bilayers

Abstract

The exchange-bias effects in the mosaic epitaxial bilayers of the itinerant ferromagnet (FM) SrRuO3 and the antiferromagnetic (AFM) charge-ordered La0.3Sr0.7FeO3 were investigated. An uncharacteristic low-field positive exchange bias, a cooling-field driven reversal of positive to negative exchange-bias and a layer thickness optimised unusual vertical magnetization shift were all novel facets of exchange bias realized for the first time in magnetic oxides. The successive magnetic training induces a transition from positive to negative exchange bias regime with changes in domain configurations. These observations are well corroborated by the hysteretic loop asymmetries which display the modifications in the AFM spin correlations. These exotic features emphasize the key role of i) mosaic disorder induced subtle interplay of competing AFM-superexchange and FM double exchange at the exchange biased interface and, ii) training induced irrecoverable alterations in the AFM spin structure.

Giant exchange bias behavior and training effect in spin-glass-like NiCr2O4/NiO ceramics

“…Therefore, it can give the true signature of the observed EB effect in NiCr 2 O 4 /NiO ceramic. Correspondingly, a negative H EB * 11.86 kOe and a positive M shift * 0.7 emu [20]. Especially, the value of H EB is much larger than the previous reported values in similar system [18].…”

Interlayer coupling through a dimensionality-induced magnetic state

“…Successive magnetic training measurements (shown in Supplementary Fig. 2) proved that the positive EB is an intrinsic effect of the heterostructure and cannot be attributed to disorder29.…”

Sol–gel synthesized BiFeO3 nanoparticles: Enhanced magnetoelelctric coupling with reduced particle size

“…The magnetic hysteresis curves of nanoparticles unveil the presence of vertical shift ( shift M ), which has been calculated using equation [21] ( …”