Effects of Cu addition on the structure and magnetic properties of L10-FePt nanoparticles prepared by sol-gel method

(FePt)(100)Cu-0, (FePt)(95)Cu-5 and (FePt)(90)Cu-10 nanoparticles (NPs) were successfully synthesized by the sol-gel method. The relationship between Cu doping and structure and magnetic properties of L1(0)-FePt NPs was studied. The results indicated that all three samples originated a L1(0)-FePt structure and Cu doping did not destroy the ordered structure of L1(0)-FePt. By increasing the Cu content, c/a ratio of the FePtCu NPs linearly decreased. Pawley refinement showed symmetry of (FePt)(95)Cu-5 NPs was still tetragonal. When the Cu concentration increased from 0 to 10 %, coercivity increased from 7,050 to 11,250 Oe. This result confirms that the prepared alloys can be promising candidates for magnetic storage applications.