Exchange bias in a magnetic ordered/disordered nanoparticle system: A Monte Carlo simulation study

We have employed the Monte Carlo (MC) simulation method to gain information on the exchange bias (EB) effect in nanoparticles composed of a ferromagnetic core and a disordered ferrimagnetic shell. The magnetic disorder of the shell affects the EB properties to the extent that they exhibit aging and training effects. The results of our MC simulations are in very good agreement with the experimental findings in a granular system composed of Fe nanoparticles (mean size 6 nm) embedded in a Fe oxide matrix confirming that the glassy nature of the shell is responsible for the observed aging and training effects.