Magnetic Tunnel Junctions Based on Out-of-Plane Anisotropy Free and In-Plane Pinned Layer Structures for Magnetic Field Sensors

• Published in: IEEE transactions on magnetics Vol. 48; no. 11; pp. 3840 - 3842
• Main Authors: Wisniowski, P., Wrona, J., Stobiecki, T., Cardoso, S., Freitas, P. P.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01-11-2012; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Anisotropic magnetoresistance; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Junctions; Magnetic hysteresis; Magnetic tunnel junction (MTJ); Magnetic tunneling; Magnetism; magnetoresistive field sensors; Materials science; Other topics in materials science; Physics; Saturation magnetization; sensing characteristics; Sensitivity; Tunneling magnetoresistance; Magnetic tunnel junction (MTJ); sensing characteristics; Anisotropy; Magnetic field effects; Magnetic fields; magnetoresistive field sensors; Magnetic properties; Tunnels
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2012.2198207

We have studied hysteresis, nonlinearity and sensitivity of CoFeB-MgO based magnetic tunnel junctions with out-of-plane and in-plane magnetizations configuration in the CoFeB free and reference layers. The configuration was achieved by using perpendicular interface anisotropy in the free and exchange bias structure in the pinned layers. For the CoFeB thickness range from 1.05 to 1.4 nm the junctions show linear transfer curves. In this CoFeB thickness range devices show linear range from ± 3 Oe to ± 1 kOe, hysteresis better than 0.6 Oe, nonlinearity 1% of the full scale and sensitivity in the range from 0.0045%/Oe to 3.8%/Oe.