Magnetic Properties of Magnetic Ultrafme Particles Synthesized from a Gaseous Mixture of Iron Pentacarbonyl and Trimethylsilyl Azide

摘要

Under UV light irradiation with a mercury lamp at 313 nm, a gaseous mixture of iron pentacarbonyl (Fe(CO)5) and trimethylsilyl azide (TMSAz) produced spherical aerosol particles with a mean diameter of 0.25 um. In the gas phase, production of hexamethyl-disiloxane was identified to support for the photochemical reactions between TMSAz and Fe(CO)4 taking place efficiently. During propagation process in aerosol particle formation, it was suggested that isocyanate (R-N=C=0) and Si-H chemical structures were produced to modify the chemical structures of aerosol particles. Under intense laser light irradiation at 355 nm with a Nd:YAG laser, a gaseous mixture of Fe(CO)5 and TMSAz produced magnetic ultrafine particles. Magnetization of the deposited ultrafme particles was measured with a SQUID magnetometer, showing that super-paramagnetic ultrafine particles were produced in addition to ferromagnetic particles under a magnetic field of 1 ~ 4.5 T. Based on the nucleation reactions induced by trimethylsilyl nitrene and iron carbonyls (Fe(CO)_n n=1~4) which were formed efficiently by two photon absorption of laser light, it was strongly suggested that ferromagnetic particles were produced via chemical reactions between trimethylsilyl nitrene and two iron carbonyls and super-paramagnetic particles, via chemical reactions between two iron carbonyls.