Anisotropy induced large exchange bias behavior in ball milled Ni-Co-Mn-Sb alloys

Abstract

We report the effect of decrease in the grain size on the structural, magnetic and exchange bias (EB) behavior in ball milled Ni(50-x)Co(x)Mn(38)Sb(12) (x=0 and 5) Heusler alloys. The existence of a wide range of grain sizes in the ball milled samples results in dramatic changes in the structural and magnetic properties. For x=0, a large EB field of 3.2 kOe is observed in the ball milled sample, compared to a value of 245 Oe of the bulk sample. This increase is attributed to the enhanced exchange coupling between the soft and hard magnetic particles. (c) 2011 American Institute of Physics. [doi:10.1063/1.3597305]