High-performance magnetoelectric composite with low DC bias magnetic field for detecting ultra-weak magnetic field

Based on a piezoelectric layer of piezoelectric macro fiber composite (MFC) and a magnetostrictive layer of iron-based amorphous or nanocrystalline alloy, a flexible laminated magnetoelectric composite magnetic field sensor has achieved ultra-high sensitivity and the detection of ultra-weak magnetic fields. The magnetoelectric sensor of amorphous alloy with lower loss (ME-A) exhibits a response voltage. The ME-A sample's optimal DC bias magnetic field has a small value of 5.04 Oe, corresponding to the magnetoelectric voltage coefficient of 18.30 V/(cm‧Oe). In addition, the ME-A sensor exhibits excellent linear response characteristics to ultra-weak AC magnetic field as low as 1.90 × 10⁻⁵ Oe at the optimal frequency of 20.50 kHz, with a sensitivity of up to 542 mV/Oe. Specifically, the ME-A sample provides real-time sensing of stepped magnetic field changes, achieving a detection resolution as low as 1.54 × 10⁻⁵ Oe. The ME-A sensor successfully detects stray magnetic fields below 1.0 × 10⁻³ Oe generated by motors at different speeds. Overall, ME-A laminated structure magnetoelectric composite with excellent magnetoelectric properties can achieve ultra-weak magnetic field detection and become a new generation of flexible magnetic field sensors.