Effect of dc-Joule-heating thermal processing on magnetoimpedance of Fe72Al5Ga2P11C6B4 amorphous alloy

The effect of multistep dc-Joule-heating thermal processing on magnetoimpedance (MI) of Fe72Al5Ga2P11C6B4 ribbons is presented. After material optimization significant increase of MI response up to value ΔZ/Z≈55% as well as sensitivity of about 6%/kA/m (for H⩽3–4 kA/m), were recorded in still amorphous samples at driving frequencies 2–3 MHz. On-line and post-annealing electrical resistivity together with Mössbauer spectra analysis and frequency dependence of the penetration depth were used for characterization of MI improvement.