A facile route to synthesis of CoPt magnetic nanoparticles

Abstract The face-centered tetragonal (FCT) ordered L1 0 CoPt nanoparticles (NPs) are prepared by the sol–gel method. Their structure and magnetic properties are characterized by the X-ray diffraction (XRD), the transmission electron microscope (TEM) and the vibrating sample magnetometer (VSM). The results indicate that the CoPt NPs heated at 400 °C are the disordered face-centered cubic (FCC) structure, whereas the samples annealed at the temperature above 600 °C exhibit an ordered FCT structure. TEM images show the increase of the particle size as the annealing temperature increases. SAED images show the appearance of the L1 0 phase at 800 °C, and the maximum coercivity is 254,720.3 A/m.