Room temperature structure evolution scanning on one ribbon-shaped sample of soft magnetic metallic metastable alloys

MOYA JAVIER A; GAMARRA CARAMELLA, SOLEDAD; BEREJNOI, CARLOS

Donostia-San Sebastian,

Simposio; 24th International Symposium on Metastable, Amorphous and Nanostructured Materials; 2017

Universidad del País Vasco

The structure evolution of some soft magnetic metastables alloys are scanned and studied through some room temperature properties changes employing only one sample submitted to successive heat treatment. The method employed was described elsewhere [1]. Small thickness of the metallic sample and Joule heating heat treatment technique are required to satisfy the method condition of low thermal inertia of the system. The heat treatment is monitored by changes occurring in room temperature magnetic properties (data obtained from hysteresis loop at 50 Hz and relative permeability at 10 kHz), room and high temperature electrical resistance and dilatometric measurements, all taken simultaneously. The method is applied to study and compare the structural evolution steps towards the optimal soft magnetic properties of three different soft magnetic alloys of our production: an amorphous alloy of composition Fe81B14Si5, and two nanocrystalline, a Finemet? (Fe73.5Si16.5B6Cu1Nb3) and a Nanomet? (Fe79Si8P4Cu1B8) ?type alloys. The amorphous alloy, as it is known, exhibits its best soft magnetic properties during the structural relaxation stage. In the case of the Finemet-type sample, the amorphous relaxation, clustering, and nanocrystallization processes are clearly observed. In this case, the best magnetic properties are obtained in the nanocrystallization stage. In Nanomet-type alloy, the optimum properties are achieved also in the amorphous relaxation stage. As an example, we present in Fig. 1 the study of the Nanomet-type sample. These results and the method applicability are discussed in this work