Tailoring of magnetic properties and GMI effect of amorphous microwires by annealing

Abstract

We studied Giant magnetoimpedance (GMI) effect and magnetic properties of amorphous Fe-Co rich as-prepared and annealed microwires. We measured the GMI magnetic field and frequency dependences, hysteresis loops and domain walls (DWs) dynamics of composite microwires produced by the Taylor-Ulitovski technique. We observed that these properties can be tailored either controlling magnetoelastic anisotropy of as-prepared CoFeBSiC microwires or controlling their magnetic anisotropy by heat treatment. High GMI effect has been observed in as-prepared Co-rich microwires. High DW velocity and rectangular hysteresis loops we observed in heat treated Co-rich microwires. We observe increasing of the DW velocity under stress in some annealed samples. At certain annealing conditions we observed coexistence of GMI effect and fast DW propagation in the same annealed sample.