Synthesis and characterization of Fe–Ti nanoparticles by nitrogen plasma metal reaction

The plasma state and nanoparticle formation of Ti–Fe alloys were studied by nitrogen plasma metal reaction. The nitrogen plasma state is dependent on the nitrogen partial pressure and the master alloy composition. Synthesis of Ti–Fe nanoparticles can be carried out only when the nitrogen partial pressure is smaller than 10% or the Ti composition is larger than 50 at.%. The as-received nanoparticles are composed of TiN and Fe phases with the mean particle diameters ranging from 25 to 40 nm; the TiN and Fe nanoparticles have quadrangular and spherical appearance, respectively. The nitrogen plasma promotes Fe evaporation more strongly than Ti, and as a result the as-received nanoparticles are Fe-rich. Compared with the hydrogen plasma, the nitrogen plasma has a smaller effect on evaporation enhancement, but stronger reactivity.