Improvement of Structural and Magnetic Properties of ${\rm L}1_{0}$ -FePd Nanocrystals by Co Addition

The effect of Co addition to magnetic properties of L1₀-FePd nanoparticles is investigated. Nanocrystalline films with Pd-Co-Fe particles were prepared by electron-beam deposition and subsequent annealing to obtain the ordered L1₀ structure. The L1₀-PdCoFe nanocrystals were formed up to 12 at% of Co concentrations with preferential c axis orientation. At higher Co concentrations, two-phase nanoparticles of L1₀-PdCoFe and bcc-CoFe were formed. The saturation magnetization is increased with increasing the Co concentration. The saturation magnetization of L1₀-Pd₅₁Co₁₂Fe₃₇ nanoparticles is estimated as 1252 emu/cm³ at room temperature. Since it possesses a decrease of L1₀ ordering temperature together with an enhancement of preferential easy axis formation and an increase of saturation magnetization, the Co addition is demonstrated the beneficial impact to L1₀-FePd nanoparticles