Detection of Single-Domain Co۲FeAl Nanoparticles Using First-Order Reversal Curve Method

Abstract

Half-Heusler nanostructures of Co2FeAl alloys, synthesized via coprecipitation route, were found to contain both hard- and soft-phases magnetic grains, mapped using first-order reversal curves (FORCs) diagrams. The obtained results confirmed that these powders are highly interacting as a single-domain magnetizing system. A significant dependence of the morphology and particle size on the annealing rate was represented by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution TEM images. The presence of the strong magnetizing interaction between the nanoparticles led to the formation of chain-like structure stabilized by PVP polymer. By increasing the annealing rate from 278.15 K/min to 288.15 K/min (5 °C/min to 15 °C/min), the grain shape changed from long nanochain to nonuniform agglomerated grains. Additionally, the magnetic characteristics of the prepared alloys were found to be affected by tuning the annealing rate.