Aging in an exchange biased Fe/FeOxide nanogranular system

A strict connection between exchange bias (EB) and aging effect was observed in a system composed of Fe nanoparticles, dispersed in a structurally disordered Fe oxide matrix showing spin-glass like properties: the exchange field measured at T=5 K can be controlled by properly varying the time, tw spent at T=50 K, after applying the cooling field. The way in which the aging of the sample influences the training effect, provides information on the underlying mechanism of the phenomenon in this system.