The magnetic phase separation and exchange bias effect in off-stoichiometric Ni2Mn1.4Ga0.6 alloy were reported. Spontaneous exchange bias after zero-field cooling was observed in this alloy. The magnetic nature of ground state was characterized as phase separation with non-percolated ferromagnetic domains in spin glass matrix due to the spatial composition fluctuation and competing ferromagnetic and antiferromagnetic interactions. A mechanism of field-induced growth of ferromagnetic domains changing from non-percolating to percolating state was proposed for the appearance of spontaneous exchange bias.

No abstract