Magnetic and Magnetoelastic Properties of Highly Magnetostrictive Amorphous Films with TbFe-FeB-TbFe Sandwich Structure

Amorphous Tb40Fe60-Fe80B20-Tb40Fe60 sandwich films were prepared by multitarget rf magnetron co-sputtering. Their magnetization and magnetostriction were studied to examine whether magnetic softening of the amorphous TbFe films could be achieved without loosing their giant magnetostriction by introducing the simple sandwich structure. The results revealed that a considerably soft in-plane magnetization (coercive force H≈ 6Oe and the squareness ratio Mr/Ms≈ 0.8) and a huge magnetostriction (λ >500ppm) could be obtained in the sandwich films at room temperature, provided that the thickness of the FeB interlayer was within the range of 10% to 40% of the total film thickness (1 μm).