Study On The Synthesis, Structure And Properties Of Monodispersed FePt Nanoparticles

FePt nanoparticles have high chemical stablity and magnetocrystallie anisotropy, and exhibit superiorities at electrochemical catalytic, magnetic properties. The supercrystal structure of FePt alloy films is good for the further development of data storage density. Therefore, it has become one of hot reseaches on magnetic recording materials.In this paper, narrow deviated in size, monodispersed FePt nanoparticles were prepared by Phase-transfer-catalysis. The transmission electron microscopy, X-ray diffraction system (XRD) and vibration sample magnetometer (VSM) were used to characterize the particle size, crystal structure and magnetic property, respectively.The TEM showed that the size of FePt nanoparticles varied after changing reaction reagents with narrow deviation, and was smaller than 20nm. After anneal treatment at 300℃, 400℃, 500℃, 600℃, 700℃ XRD indicated the FePt nanopartles phase changed from fcc to fct ordered L1₀ strucure at about 400℃, and amount to top at 600℃. As shown in the magnetic hysteresis loops of FePt nanoparticles, the coervicity changed from 5Oe to 2400Oe after anneled at 600℃ for 0.5h. Moreover, by using siloxane and 1,6-hexanedithol as crosslink, Pt/FePt multilayer films were fabricated through layer-by-lay (LBL) self-assembly method. Ultra Violet/Visible Spectrophotomete (UV-Vis) and field emission scanning electron microscope (FESEM) were used to note the state of interlayers and the surface of FePt multilayer films, respectively. Because Pt alloy catalysts can improve the redox reaction in 0.5M H₂SO₄/0.5M CH₃OH system, we here keep on studying on the electrocatalytic activity of FePt nanoparticles in the same system, as a result, electrochemical experiment illustrated the FePt nanoparticles had better catalytic behavior than Pt particles.