Effects of high magnetic field on the growth and magnetic property of L10-FePtCu nanoparticles

Developing a novel strategy for promoting the disorder-order transition of FePt nanoparticles (NPs) is helpful to improve magnetic and electrocatalytic properties of the FePt NPs. In this research, high magnetic field (HMF) was introduced to wet-chemical synthesis of the L1(0)-FePt NPs. The effects of HMF on the growth and magnetic property of wet-chemical synthesized L1(0)-FePtCu NPs were studied. Cu atoms preferred to occupy the Fe-site in L1(0)-FePt lattice at 6 T HMF, which facilitated this disorder-order transition and increased the ordering degree of L1(0)-FePtCu NPs. When the magnetic dipolar interaction energy was much higher than the thermal energy, the HMF also enhanced the orientation attachment of L1(0)-FePtCu NPs along < 001 > direction, which would lead to the increasing of growing rate and the aligning of NPs. The HMF increased the coercivity of L1(0)-FePtCu NPs by increasing the grain size and the ordering degree. This work provides a promising method for controlling the disorder-order transition, the attachment growth, and the magnetic property of wet-chemical synthesized NPs.