Preparation and Properties of ε-Fe(3)N-Based Magnetic Fluid

In this work, ε-Fe(3)N nanoparticles and ε-Fe(3)N-based magnetic fluid were synthesized by chemical reaction of iron carbonyl and ammonia gas. The size of ε-Fe(3)N nanoparticles was tested by TEM and XRD. Stable ε-Fe(3)N-based magnetic fluid was prepared by controlling the proper ratio of carrier liquid and surfactant. The saturation magnetization of stable ε-Fe(3)N-based magnetic fluid was calculated according to the volume fraction of the particles in the fluid. The result shows that both the calculated and measured magnetizations increase by increasing the particle concentration. With the increasing concentration of the ε-Fe(3)N particles, the measured value of the magnetic fluid magnetization gradually departs from the calculated magnetization, which was caused by agglomeration affects due to large volume fraction and large particle size.