Analysing the magnetic disorder around ferromagnetic nanoprecipitates within an antiferromagnetic matrix

Ni50Mn45In5 alloy decomposes into nanosized Ni50Mn25In25 precipitates which become embedded in a Ni50Mn50 matrix when annealed at temperatures between about 650 and 750 K under a magnetic field > 0.1T. The precipitates have a Curie temperature of around 320K and are ferromagnetic at room temperature, whereas the matrix is antiferromagnetic. In a previous small-angle neutron scattering (SANS) study of such a sample, we found that the ferromagnetic nanoprecipitates (which are around 55 nm in size) represent sources of perturbation, which seem to give rise to magnetically disordered regions in the vicinity of the particle-matrix interface. Here, we want to use SANS to systematically study the influence of external magnetic fields and temperature on the magnetically disordered regions around the nanoprecipitates.