Evolution of Magnetomechanical and Magnetic Properties of Siliconized Iron-Silicon Alloys by CVD Process Using SiCl4

Abstract

Non-oriented and grain-oriented 6.5% Si-Fe laminations have been prepared by means of the dynamic Chemical Vapour Deposition technique, exploiting a chemical reaction at 1000°C between a flowing SiCl 4 + Ar mixture and an iron-silicon based substrate. The siliconizing process leads, from the first moments, to an epitaxial growth of Fe 3 Si, then to an underlayer solid solution by intermetallic diffusion. The optimum treatment has been chosen as 60 minutes at 1000°C, followed by 13 hour annealing in vacuum at the same temperature, which permits one to achieve the desired uniform concentration of Si around 6.5 wt %. NO and GO treated samples have been magnetically characterized in the frequency range 0.5 Hz - 1 kHz. A decrease between 15% and 50% of the energy loss has been observed in the CVD laminations.