Magnetic properties of Fe76X2Si8B14 (X= Al, Cr, Mo) amorphous alloys

Abstract

Purpose: The idea of the paper is to study the influence of thermal annealing and alloying additions on magnetic properties, optimization and crystallization processes in Fe76X2Si8B14 (X=Al, Cr, Mo) amorphous alloys. Design/methodology/approach: For annealed samples (1 h, Ta ranging from 300 K to 800 K) at room temperature magnetic permeability was measured by applying Maxwell-Wien bridge (frequency about 1030 Hz and magnetic field H=0.5 A/m). Magnetostriction coefficients – parallel and perpendicular were determined by applying infra-red magneto-dilatometer. Magnetization in saturation versus temperature was measured by making use of magnetic balance (field 0.5 T). Findings: It was shown that alloying additions in the examined alloys cause a decrease of the Curie temperature, an increase of magnetic permeability and magnetization in saturation. The observed ESMP (enhancement of soft magnetic properties) effect in the examined alloys can be attributed to the so-called relaxed amorphous phase free iron nanograins. It was shown that parallel and perpendicular magnetostriction coefficients depend on annealing temperatures which means that these quantities are sensitive on free volume content. Research limitations/implications: The obtained results are a part of a broad area of examinations devoted to establishing of the influence of different alloying additions and thermal annealing on soft magnetic properties of amorphous alloys obtained by melt spinning technique. Practical implications: The examined alloys belong to a modern group of soft magnetic materials, which can be used as core transformers, magnetic sensors, shields of magnetic etc. The obtained results may be used for preparing soft magnetic ribbons for specific applications. Originality/value: The originality of the paper lies in examination of the influence of free volume content on magnetostriction coefficients.