Magnetostriction under high prestress in Fe81Ga19 crystal.

Seeking high precision actuator and transducer materials potentially applied under high load remains active in recent years. Magnetostrictive property, magnetostriction saturation field HS, and pizeomagnetic coefficient d33 are investigated in Fe81Ga19 alloy under high compressive prestress. The measured saturation magnetostriction remains above 300 ppm in the <001> oriented Fe81Ga19 polycrystalline rod under high compressive prestress up to 431 MPa. Two-stage phenomenon was observed in curves plotted for HS and d33 against compressive prestress σ. The domain rotation path and magnetostriction under different compressive prestress are simulated, and this helps to deeply understand the tested magnetostriction. Based on the simulation, the mathematical equations of HS-σ and d33-σ were established for Fe–Ga <001> oriented crystal revealed two mechanisms, which satisfy proposed functions of experimental data. The high magnetostriction and low saturation field under high prestress indicate that Fe–Ga alloy is possible to be a sound candidate for high load application. [ABSTRACT FROM AUTHOR]