Tailoring magnetostriction with various directions for directional solidification Fe82Ga15Al3 alloy by magnetic field heat treatment

The magnetostriction of the Fe82Ga15Al3 alloy, along the length and width, can be tailored by applying a magnetic field heat treatment. In this work, the Fe82Ga15Al3 sheet was cut from the directional solidified Fe82Ga15Al3 alloy with the < 100 > preferred orientation and was annealed at 720 degrees C for 30 min under a magnetic field of 800 Oe along the length direction with a heating and cooling rate of 100 degrees C/min. The magnetostrictive properties along the length and width directions were modified to lambda(parallel to) = 7 ppm and lambda(perpendicular to) = -210 ppm from lambda(parallel to) = 210 ppm and lambda(perpendicular to) = -10 ppm for the initial sample prior to the magnetic field heat treatment. The cellular-like magnetic domain structure was composed of parallel 180 degrees stripe domains and vertical 90 degrees domains observed using a magnetic-force microscope. The change in magnetostriction along parallel and perpendicular directions was mainly resulted from the rotation of the magnetic domain units. Published by AIP Publishing.