Magnetic and Structural Characterizations of Co-based Heusler Nanoparticles Fabricated via Simple Co-precipitation Method

Nanoparticles of Co₂FeAl magnetic alloy was successfully fabricated in the presence of a well-known capping agent, polyvinyl alcohol, as a polymer template. The magnetic properties were studied using hysteresis curve and first-order reversal curve (FORC) measurements at room temperature. FORC diagrams demonstrated a wide distribution of the coercive field owing to the presence of different particle sizes in products. TEM image also showed that the synthesized samples are composed of some large clusters containing a few smaller particles. The maximum value of magnetization (~76 emu/g) and coercivity (573 Oe) were obtained in the annealed sample with 5 °C/min. A wider distribution of grain size with a smaller average of 20.5 nm as well as lower-degree of crystallinity was observed in the sample annealed with higher rate of 10 °C/min.