Self-Assembly and Magnetic Properties of FePt, FeRh Nanoparticles, and FePt/FeRh Nanocomposite Particles

FeRh nanoparticles with the composition of Fe
₇₅
Rh
₂₅
and Fe
₃₆
Rh
₆₄
have been fabricated by a solution phase chemical method. After refining and size selection, a particle size is about 2 to 5 nm by HRTEM observation. From XRD results, as-deposited FeRh nanopaticles reveal a typical chemically disordered fcc structure which can be transformed into CsCl-type structure through thermal annealing. In the case of annealed Fe
₆₄
Pt
₃₆
nanoparticles, the perpendicular coercivity increases comparing with that of as-deposited particles. It may be the results of the crystal orientation of fct-phase