The Surface Structure and Magnetic Properties of Amorphous and Nanocrystalline Microwires Based on an Iron Alloy of Multicomponent Composition

This paper presents the experimental study of the structural and magnetic characteristics of amorphous and nanocrystalline microwires of $Fe_{73.8} Cu_{1} Nb_{3.1} B_{9.1} Si_{13}$ composition with a diameter of 25 μm. All amorphous microwires were made by the Ulitovsky-Taylor method and covered with glass insulation. Nanocrystalline microwires were obtained by annealing at a temperature of 550 °C for 60 minutes. The structure, diameter, and elemental composition of the obtained amorphous microwires were studied by using a Zeiss Supra 50 VP scanning electron microscope and X-ray diffraction analysis method on a Siemens D-500 diffractometer. The measurements of the magnetic dependences of all microwires were obtained on a vibrating sample magnetometer P.A.R. 155 with an external magnetic field strength up to 800 Oe. It was found, that during microwire nanocrystallization, the coercive force decreases and the hysteresis loop squareness increases. The MOIF method developed in this work for checking the microwire for the anisotropy of magnetic properties relative to the axis of its rotation helped to establish the demonstration of a transverse anisotropy that is asymmetric relative to the axis of the microwires that occurs in a significant distortion of a form of hysteresis loops during 90° and 270° rotations around the longitudinal axis.