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Permanent-Magnet-Free Stabilization and Sensitivity Tailoring of Magneto-resistive Field Sensors



Sean Halloran, Fabio C. da Silva, Hamid Z. Fardi, David P. Pappas


In this work, we have exploited the coupling across a ruthenium spacer between a ferromagnetic layer and an antiferromagnetic layer to stabilize the magnetization and tailor the magnetic gain of the sensor for various applications. Because the structure is deposited as a single stack, it significantly reduces the number of patterning steps relative to a permanent magnet biased scheme. Ruthenium is used as the buffer layer and is self aligned with the ferromagnetic (NiFe) free layer and antiferromagnetic (IrMn) pinning layer and the thickness is varied to change the slope of the transfer curve in the linear region, i.e. the sensitivity. The results show that this biasing scheme is well suited for barber pole and soft adjacent layer anisotropic magnetoresistance sensing elements used in magnetic field sensors.
Journal of Applied Physics


Halloran, S. , da Silva, F. , Fardi, H. and Pappas, D. (2007), Permanent-Magnet-Free Stabilization and Sensitivity Tailoring of Magneto-resistive Field Sensors, Journal of Applied Physics, [online], (Accessed April 24, 2024)
Created August 1, 2007, Updated October 12, 2021