Crystal growth of Fe81Ga19 alloy and its magnetostrictive properties

摘要

We have investigated the crystal growth of Fe81Ga19 alloy by using optical zone melting furnace systematically. The two important processing parameters, growth velocity and rotation rate, varied from 2 to 27 mm/h and from 5 to 30 r/min, respectively. The stability of melting zone is the key factor for single crystal growth. We successfully prepared oriented polycrystalline and single crystal of Fe81Ga19 alloy by regulating the growth velocity and rotation rate properly. X-ray pole figure was employed to determine the grain orientation, and [110] orientation within 15o away from the rod axis was obtained in FeGa rods with growth velocities of 5 and 10 mm/hr, while [100] orientation within 15o and 20 o away from the rod axis for growth velocity of 2 and 27 mm/hr. The competition and selection of grains during single crystal growth was analyzed by observation of optical micrography. The magnetostriction properties of crystals with different growth processes were measured by standard stain gauge.