Dependence of exchange bias on core/shell relative dimension in ferromagnetic/antiferromagnetic nanoparticles

•Dependence of exchange bias on core/shell relative dimension is studied.•Antiferromagnetic (core)/ferromagnetic (shell) nanoparticles are exploited.•A modified Metropolis Monte Carlo simulation is employed.•Exchange bias behaviors with core/shell relative dimension are intriguing in nanoparticles.

We employ a modified Metropolis Monte Carlo simulation to study the effect of bimagnetic core/shell relative dimension on exchange bias in ferromagnetic/antiferromagnetic nanoparticles. The exchange bias field is inversely proportional to the ferromagnetic shell thickness in the antiferromagnetic (core)/ferromagnetic (shell) nanoparticles, while in the nanoparticles with an opposite core/shell structure the exchange bias behavior is complex and distinguished in different ranges of the ferromagnetic core radius. The work elucidates unambiguously how the core and shell dimensions optimize the exchange bias in nanoparticles.