Flame synthesis of superparamagnetic Fe/Nbnanocomposites for biomedical applications

摘要

Ironiobium nanocomposite particles are produced using the sodium flame and encapsulation (SFE) process.Ferrocene is added to the vapor-phase metal halide/sodium reaction to produce metallic iron particlesencapsulated in niobium. To accomplish this, the ferrocene is combined with niobium chloride vapor and thismixture is injected as a turbulent jet into a stream of sodium vapor. The ferrocene is expected to decomposeupstream of the flame to form iron particles, which pass through the niobium chloride-sodium reaction zonewherein they are encapsulated in niobium. The salt byproduct then encapsulates these particles, preventingoxidation. The as-produced Fe/Nb particles were found to contain Fe particles that are less than ～15 nmin diameter and are superparamagnetic with a coercivity of 50 Oe and a saturation magnetization of over200 emu/g of Fe. In addition to possessing a strong magnetic response and small remnant magnetization,the ironiobium composite particles are expected to be biocompatible and X-ray opaque. Consequently,these materials hold promise for magnetic navigation in biomedical applications.