On the L10 Ordering Kinetics In Fe-Pt Nanoparticles

In this presentation, we quantify the minimum times required to obtain the L1₀ phase in in-flight annealed FePt nanoparticles. After their gas phase preparation by means of inert gas condensation in Ar, the particles are carried with a continuous Ar gas flow through an annealing furnace (diameter = 38 mm, length = 0.7 m). The gas flow rate and pressure are typically 100 sscm and 1 mbar, respectively. We have calculated the velocity and temperature profiles of the Ar gas along the annealing furnace by means of a computational fluid dynamics software package ("Fluent"), since at typical particle sizes of some 5 nm, the particles are in thermal equilibrium with the carrier gas within less that a millisecond, the obtained results can be immediately transferred to the particles themselves.