Micro-patterned NiFeMo Magnetoimpedance Multilayer for Magnetic Sensor Application

As an alternative to the magnetoimpedance (MI) devices made from amorphous ribbon or wire, this study proposed a thin film type MI device composed with Ag conductive core and soft ferromagnetic NiFeMo sandwich layers. Obtained optimum sandwich structure was Ta 5 nm/ NiFeMo 300 nm/ Ta 5 nm/ Ag 900 nm/ Ta 5 nm/ NiFeMo 300 nm/ Ta 5 nm, and the width of Ag as 20 µm and the width of NiFeMo as 100 µm. It was patterned by using photolithography and lift-off process. The sandwich structure showed the maximum MI ratio about 40% at the 15 MHz. The impedance change was linear and nearly reversible at the external magnetic field region below the anisotropy field.