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 L1
₀
-FePd nanoparticles is investigated. Nanocrystalline films with Pd-Co-Fe particles were prepared by electron-beam deposition and subsequent annealing to obtain the ordered L1
₀
structure. The L1
₀
-PdCoFe nanocrystals were formed up to 12 at% of Co concentrations with preferential c axis orientation. At higher Co concentrations, two-phase nanoparticles of L1
₀
-PdCoFe and bcc-CoFe were formed. The saturation magnetization is increased with increasing the Co concentration. The saturation magnetization of L1
₀
-Pd
₅₁
Co
₁₂
Fe
₃₇
nanoparticles is estimated as 1252 emu/cm
³
at room temperature. Since it possesses a decrease of L1
₀
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 L1
₀
-FePd nanoparticles