Room and ‘in situ’ high-temperature Mössbauer study of ordering in Fe–Si (0–22 at%) alloys

Abstract

Fe–Si alloys are known to have excellent soft magnetic properties , especially around 6.5 wt% Si (12.1 at%). Nevertheless, above 3.5 wt% (6.7 at%) the material becomes very brittle and this has prevented its mass production. It has been usually reported that the cause of this phenomenon lies on a disorder–order transition, with three ordered situations involved, namely A2, B2 and D0 3 . Room and ‘in situ’ high-temperature Mössbauer spectroscopy up to 600°C was carried out on Fe–Si alloys with a Si content varying from 0 to 22 at% Si in order to find out information about these ordering phenomena. Results show that the increasing temperature in low-Si alloys (4 at%) only slightly influences ordering, while an increase of B2 and D0 3 order is found for higher Si contents (10–14 at%) between 450°C and 600°C.