Longitudinal and Transverse Magnetoimpedance in FeNi/Cu/FeNi Multilayers With Longitudinal and Transverse Anisotropy

Longitudinal and transverse magnetoimpedance is studied for Fe₁₉Ni₈₁ (150 nm)/Cu(500 nm)/Fe₁₉Ni₈₁ (150 nm) multilayered structures with exactly the same geometry, having either longitudinal or transverse magnetic anisotropy, at frequencies up to 500 MHz, convenient enough for technological applications. The highest sensitivity was observed for longitudinal magnetoimpedance of the structures with transverse magnetic anisotropy. Transverse magnetoimpedance ratio for structures with transverse magnetic anisotropy was small but transverse magnetoimpedance and its sensitivity for the structures with longitudinal magnetic anisotropy was quite high. Relatively high values of transverse and longitudinal magnetoimpedance for the structures with longitudinal anisotropy lead to the possibility to design a single sensitive element detector for the control of the magnetic fields, parallel and perpendicular to the element.