Magnetic properties of FINEMET alloys doped with niobium

Abstract

The present Master thesis is devoted to investigation of annealing effects on magnetic properties and microstructure of nanocrystalline FINEMET alloys doped with niobium. Nowadays, the research of new types of soft magnetic materials is a widely discussed topic due to their importance in the field of magnetic devices, such as: EMI filters, magnetic sensors, high frequency power transformers, etc. The thesis is focused on the studies of magnetic characteristics of FINEMET alloys doped with niobium with emphasis on choosing the films with the most suitable parameters for practical application. The research was done by means of SQUID magnetometery, RAMAN spectroscopy, atomic force microscopy and X-ray diffractometry. It was found that annealing at temperature of 450°C lead to the highest level of crystallization Fe3Si . The films showed very strong uniaxial anisotropy induced by the application of in-plane field during the film deposition process. The obtained good soft magnetic properties of the FINEMET films are well suited for practical applications.