Magnetic emission intensity enhancement for amorphous alloys by constructing a multi-phase structure with α-Fe nanocrystals

The perturbation in the magnetic field generated by the rotation or oscillation of magnetic domains in magnetic materials can emit low-frequency electromagnetic waves, which are expected to be used in low-frequency communications. However, the magnetic emission intensity, defined by the perturbation ability, of current commercially applied amorphous alloys, such as Metglas, cannot meet the application requirements for low-frequency antennas due to the domain motion energy loss. Herein, a multi-phase Metglas amorphous alloy was constructed by incorporating α-Fe nanocrystals using rapid annealing to manipulate the domain movement. It was found that 3.89 times higher magnetic emission intensity is obtained compared to the pristine due to the synergism of the deformation and displacement mechanisms. Moreover, the low-frequency magnetic emission performance verification was carried out by preparing magnetoelectric composites as the antenna vibrator by assembling the alloy and macro piezoelectric fiber composites (MFC). Enhancements of magnetic emission intensity are found at 93.3% and 49.2% at the first and second harmonic frequencies compared with the unmodified alloy vibrator. Therefore, the approach leads to the development of high-performance communication with a novel standard for evaluation.