Co₉₀P₁₀ Sensing Elements Based on the Giant Magnetoimpedance Effect for Biomedical Applications*

Magnetic field sensors based on the Giant Magnetoimpedance (GMI) effect offer accuracy, low cost, compact size, and room-temperature operation. The GMI is characterized by a remarkable variation in the impedance of certain materials when exposed to external magnetic fields, especially amorphous ferromagnetic conductors. Among the various applications for these sensors, we are interested in their use for detecting lost metals in human bodies, detecting cancerous cells via magnetic nanoparticles, and measuring biomagnetic fields. In this work, we electrodeposited GMI sensing elements of a soft ferromagnetic conductive material, Co₉₀P₁₀, in the form of microtubes on a copper (Cu) wire and in the geometry of rectangular meanders on a sputtered Cu trail over a glass substrate. We characterized the composition, surface quality, and electrical and magnetic properties using Energy-dispersive spectroscopy (EDS), Impedance Analyzer, and VSM techniques. Our preliminary results show Co₉₀P₁₀ microtubes exhibit good magnetic behavior, uniform adherence to the copper wire, smooth surface, and a proportion of 89% cobalt to 11% phosphorus. We expect to tune the sensitivity of these sensors by controlling growth processes and geometrical parameters.