Enhanced magnetoimpedance effect of carbon fiber/Fe-based alloy coaxial composite by tensile stress

Carbon fiber/Fe-based soft magnetic alloys coaxial composites have been prepared and the enhanced giant magnetoimpedance effect has been investigated by applying a tensile stress. Carbon fibers as the inner core are commercially available, the outer layers respectively are Fe, Ni, FeNi and FeCo alloys, which are fabricated by electrochemical deposition. The composite with Fe80Ni20 alloy shows the best static magnetic property and giant magnetoimpedance ratio (about 26%) compared to other metals or alloys without tensile stress at 70 MHz. When applying a tensile stress, the giant magnetoimpedance ratios of all samples show large improvements. With the increase of the tensile stress, the ratio increases to the maximum value (about 200%) when the tensile stress is 350 MPa, which is about eightfold over the original sample and higher than traditional materials.