High-performance vibration power generation using polycrystalline Fe–Co-based alloy due to large inverse magnetostrictive effect

摘要

The magnetic flux density change Δ B caused by the inverse magnetostrictive effect is key for achieving high-performance vibration power generation. As the magnetization curve of the polycrystalline Fe–47.6 at.?% Co–2.3 at.?% V (Fe–Co–V) alloy became easier to magnetize by applying tensile stresses, the value of Δ B estimated from the magnetization curves depended significantly on magnetic fields. Hence, the vibration power generation of a U-shaped unimorph device using a polycrystalline Fe–Co–V alloy core was demonstrated under various bias magnetic fields. As a result of bias magnetic field adjustment, the open-circuit voltage induced by the vibration of the device improved to ～7.0?V. Such superior performance is attributable to a large Δ B of 1.1?T in the Fe–Co–V alloy core. Therefore, adjustment of bias magnetic fields is essential for obtaining large Δ B in Fe–Co–V alloys, which are promising inverse magnetostrictive materials for high-performance vibration power generation.