The Study of Magnetically Soft Fe–B–P Based Nanostructures

Abstract

Rapidly quenched Fe–B–P alloys with addition Cu exhibit high saturation induction, high permeability, low coercivity, and excellent mechanical properties (Svec et al. in IEEE Trans. Magn. 46:408, 2010; Makino et al. in IEEE Trans. Magn. 45(10):4302–4305, 2009; Makino et al. in Ser. Mater. 48:869, 2003). The systems based on Fe–B–P–Cu have been prepared by planar flow casting in form of thin ribbons. Selected magnetic properties in the as-cast state and after controlled annealing targeted to produce fine-grain structure of bcc-Fe in amorphous matrix were determined. The effect of the additions of P and Cu on structure and soft magnetic properties in the nanocrystalline state was investigated. Using the direct magnetostriction measurement method, the magnetostrictions as functions of external magnetic field in parallel and perpendicular directions were determined and the values of saturation magnetostriction λs were calculated. The Curie temperature was determined by thermogravimetry analysis (TGA). X-ray diffraction (XRD) and transmission electron microscopy (TEM) investigations at selected temperatures were performed to obtain information about the structure, morphology, size, and distribution of grains in an amorphous matrix, and to correlate microstructure and selected physical properties of the investigated system.