Title :
Spin-dependent tunneling junctions with superparamagnetic sensing layers
Author :
Wang, Dexin ; Daughton, Jim M. ; Qian, Zhenghong ; Tondra, Mark ; Nordman, Cathy
Author_Institution :
NVE Corp., Eden Prairie, MN, USA
Abstract :
Spin-dependent tunneling (SDT) junctions with superparamagnetic (SPM) sensing layers have been made using sputtering deposition and photolithography fabrication techniques. The SPM-SDT junctions have zero hysteresis with reasonable sensitivity, and the output signal is bipolar relative to the external magnetic field without using any biasing-an inherent advantage in using a unidirectional pinned layer and an in-plane-isotropic SPM free layer in the SDT structure. This novel SPM-SDT junction is the first of its kind ever reported and offers great potential for commercial applications. The SPM-SDT devices are especially suitable for low-power and low-field applications such as solid-state compassing, magnetic medium detection, nondestructive evaluation, biomedical sensing, and mobile electronics device applications.
Keywords :
biomedical measurement; magnetic field measurement; magnetic multilayers; magnetic sensors; magnetic tunnelling; nondestructive testing; photolithography; spin polarised transport; sputtered coatings; superparamagnetism; biomedical sensing; bipolar output signal; external magnetic field; magnetic medium detection; mobile electronics device applications; nondestructive evaluation; photolithography fabrication techniques; solid-state compassing; spin-dependent tunneling junctions; sputtering deposition; superparamagnetic sensing layers; unidirectional pinned layer; zero hysteresis; Fabrication; Magnetic anisotropy; Magnetic fields; Magnetic hysteresis; Magnetic separation; Magnetic tunneling; Perpendicular magnetic anisotropy; Scanning probe microscopy; Solid state circuits; Sputtering;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2003.815720
