On the Measurement of Permeability and Magnetostriction in Ribbons and Wires

The magnetostrictive delay line (MDL) principle is used to evaluate the magnetic and magnetostrictive properties of materials with waveguide-like shape, such as ribbons and wires. The material under test is used as the MDL on which a pulsed field along with a dc bias field is applied at the excitation point while another dc bias field is applied at the receiving end. Theoretical analysis shows that varying the dc bias field at the receiving end while keeping the excitation field constant results in the dc differential permeability measurement, the integral of which yields the dc hysteresis loop of the material, i.e., B(H). The response obtained upon varying the dc bias field at the excitation point, while keeping all else constant, is proportional to the derivative with respect to field of the dc magnetostriction loop, i.e., λ(H). The theoretical analysis is supported by experimental results obtained on FeSiB wires and ribbons.