Tunable giant exchange bias in single-phase rare earth-transition metal intermetallics YMn12-xFex with highly homogenous inter-sublattice exchange coupling

摘要

In this paper, we have found a family of intermetallic compounds YMn12-xFex(x = 6.6-8.8) showing a bulk form of tunable giant exchange bias effect whicharises from global interactions among ferromagnetic (FM) and antiferromagnetic(AFM) sublattices but not the interfacial exchange coupling or inhomogeneousmagnetic clusters. A giant exchange bias with a loop shift up to 6.1 kOe hasbeen observed in YMn4.4Fe7.6 compound with the strongest competing magneticinteractions. In a narrow temperature range, the exchange bias field shows asudden switching off whereas the coercivity shows a sudden switching on withincreasing temperature. This unique feature indicates that the inter-sublatticeexchange coupling is highly homogenous, which can be perfectly interperated byour theoretical calculations.