Production and magnetic properties of in situ oligomer coated α-Fe nanoparticles in the gas phase

We report on the production and characterization of the magnetic properties of in situ oligomer coated α-Fe nanoparticles. Although a polymer cannot be used to in situ coat iron nanoparticles in the gas phase due to its low vapor pressure, an oligomer (i.e., a low mass polymer) may be used for this purpose because it has enough vapor pressure. Besides surface protection, functional molecules such as ligands, peptides, antibodies, and DNA can be also easily bound to an oligomer, which will be extremely useful for further advanced applications. We in situ coated α-Fe nanoparticles with a dimethylsilylenesiloxane oligomer in the gas phase by thermally decomposing Fe (CO) 5 as a precursor of α-Fe nanoparticles with a resistive heater in the presence of dimethylsilylenesiloxane oligomer vapor. These core-shell nanoparticles ranging from 5 to 15 nm in core α-Fe nanoparticle diameter showed saturation magnetization as high as 68 emu/g and coercivities as large as 1338 and 381 Oe at 10 and 300 K, respectively.