Susceptibility Spectroscopy in FeNiSiB Microwires

Abstract

Amorphous magnetic microwires are novel materials, which are characterized by unusual soft magnetic properties, such as magnetic bistability and Giant MagnetoImpedance (GMI) effect [1]. The magnetic behavior of this microwire strongly depends on their composition, which is directly responsible of the sign and magnitude of magnetostriction constant, and also on the values and distribution of internal stresses induced during preparation [2]. The magnetic properties of amorphous microwires are usually described in terms of the core-shell model [3]. In accordance with the model, a microwire with positive magnetostriction consists of one large axial domain surrounded by the outer domains with radially oriented magnetization. Measurement of the amplitude dependence of the complex susceptibility is a useful method for studying dynamic magnetization processes in ferromagnetic materials because the magnetization processes can be resolved [4, 5]. We apply this method here to study the magnetization process in amorphous glass-coated FeNiSiB microwires with different Fe/Ni ratios.