Piezomagnetic behavior of Fe–Al–B alloys

• Piezomagnetic behavior of Fe–Al–B alloys is determined for the first time.
• Alloys with 14% of aluminum phase have the optimized piezomagnetic behavior.
• The Fe2B phase improves the piezomagnetic properties.
• Fe–Al–B initial susceptibility is higher at low fields than in pure Fe–Al alloys.

For the first time, the piezomagnetic behavior of polycrystalline Fe-Al-B alloys is accessed. Piezomagnetic factors of up to 4.0 kA m−1/MPa were reached for an interval of applied compressive stresses between 0 and −140 MPa. The experimental results together with a powerful multiscale and biphasic modeling allowed the general understanding of the magnetostrictive and piezomagnetic behaviors of these materials. The magnetic and mechanical localizations as well as homogeneous stresses were considered in the modeling and are associated to the intrinsic presence of the Fe2B phase. The interplay of the magnetocrystalline anisotropy, initial susceptibility, saturation magnetostriction and texture were quantified by the model and compared to the experimental results. An improvement of the piezomagnetic factor to 15 kA m−1/MPa is predicted, for an alloy containing 20% of aluminum, by getting an adequate texture near 〈100〉〈100〉 directions.