Development of magnetostrictive foil with nano multilayer-hetero magnetic domain driven by lower magnetic field

1. 超磁致伸缩Fe-Ga合金具有较高的速度和磁致伸缩产生的巨大应力，有望作为致动器/传感器材料。为了制备低磁场诱导磁致伸缩材料，采用磁控溅射系统制备了Fe_<80>Ga_<20>带(146 μm)/ Ni （14 μm）薄膜的磁致伸缩（正磁致伸缩/负磁致伸缩）双晶层。采用快速凝固法制备Fe_<80>Ga_<20>带。采用光学杠杆法测量了悬臂式薄膜的磁致伸缩性能。在40 kAm^<-1>的低稳定磁场下，长度为22 mm的箔的上部位移为530 pin，并表现出。-小滞后。这些磁致伸缩特性在低频交变磁场下也能保持。此外，在机械共振频率下，箔片的位移出现峰值，在周磁场为50 oe时达到2.0 mm。将磁致伸缩双晶层应用于微气阀。这些悬臂式驱动器可以通过施加与长度平行的磁场来弯曲。在500oe下，执行器的一个点位移约300 μm。由磁致伸缩执行器组成的气阀的启闭动作可以通过磁场远程控制。当磁场增加到3500e时，气体的流量可达到50 ~ 0 cc min^<-1>。施加磁场后响应时间小于0.15秒，速度快：

1. Giant magnetostrictive Fe-Ga alloys are expected as actuator/sensor materials with high respective velocity and huge stress created by the magnetostriction. In order to develop magnetostrictive material induced by low magnetic field, we investigated magnetostrictive (positive magnetostriction / negative magnetostriction) bimorph-layers, that is, Fe_<80>Ga_<20> ribbon (146 μm)/ Ni (14 μm) film by magnetron sputtering system. The Fe_<80>Ga_<20> ribbon was prepared by rapidly solidification. Magnetostrictive property of the cantilever-type foil was measured using an optical lever method. Displacement of the upper part of the foil with length of 22 mm was 530 pin under low steady magnetic field of 40 kAm^<-1> and exhibits.- little hysteresis. These magnetostrictive properties also are maintained under low frequency of alternating magnetic field. Moreover, the displacement of the foil at the mechanical resonance frequency exhibits a peak and reaches to 2.0 mm at week magnetic field of 50 Oe.2. The, magnetostrictive bimorph-layers was applied to micro-gas valve. These cantilever-type actuators can be bent by applying magnetic field parallel to length. A point of the actuator displaced about 300 μm under 500 Oe. The opening and closing action of a gas-valve consisted of magnetostrictive actuator can be controlled remotely by magnetic fields. Flow rate of gas can be driven 50 to 0 cc min^<-1> upon increasing magnetic field to 3500e. Response time after applying of magnetic field is below 0.15 sec, it is fast: