Arrays of interacting ferromagnetic nanofilaments: Small-angle neutron diffraction study

Magnetic properties of spatially ordered arrays of interacting nanofilaments have been studied by means of smallangle diffraction of polarized neutrons. Several diffr action maxima or rings that correspond to the scat� tering of the highly ordered structure of pores/filaments with hexagonal packing have been observed in neu� tron scattering intensity maps. The interference (nuclearmagnetic) and pure magnetic contributions to the scattering have been analyzed during the magnetic reversal of the nanofilament array in a field applied per� pendicular to the nanofilament axis. The average magnetization and the interference contribution propor� tional to it increase with the field and are saturated at H = H S. The magnetic reversal process occurs almost without hysteresis. The intensity of the magnetic contribution has hysteresis behavior in the magnetic reversal process for both the positive and negative fields that form the field dependence of the intensity in a butterfly shape. It has been shown that this dependence is due to the magnetostatic interaction between the filaments in the field range of H ≤ HS. A theory for describing the magnetic properties of the arrays of interacting ferro� magnetic nanofilaments in the magnetic field has been proposed.