Linearization and Field Detectivity in Magnetic Tunnel Junction Sensors Connected in Series Incorporating 16 nm-Thick NiFe Free Layers

Author

Janeiro, Ricardo J. ; Gameiro, Luís ; Lopes, António ; Cardoso, Susana ; Ferreira, Ricardo ; Paz, Elvira ; Freitas, Paulo P.

Author_Institution

INESC-MN & IN, Lisbon, Portugal

Volume

48

Issue

11

fYear

2012

Firstpage

4111

Lastpage

4114

Abstract

In this work, arrays of MgO-based magnetic tunnel junction elements (5×20 μm²) connected in series are studied for sensor applications. Linearization is obtained by combining shape anisotropy with a longitudinal hard bias field set by CoCrPt permanent magnets integrated on the sides of the array. We show that this architecture has the drawback of a large footprint in the chip, but is largely compensated by the weak bias voltage dependence and huge electric robustness, when comparing with individual magnetic tunnel junctions.

Keywords

chromium alloys; cobalt alloys; iron alloys; magnesium compounds; magnetic anisotropy; magnetic sensors; magnetic tunnelling; nickel alloys; permanent magnets; platinum alloys; CoCrPt; MgO; NiFe; field detectivity; free layers; longitudinal hard bias field; magnetic tunnel junction sensors; permanent magnets; sensor applications; shape anisotropy; size 16 nm; weak bias voltage dependence; Junctions; Magnetic sensors; Magnetic tunneling; Noise; Sensitivity; Tunneling magnetoresistance; Detectivity; MTJ series; MgO magnetic tunnel junctions; noise level; sensitivity; tunneling magnetoresistance sensors;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2012.2202887

Filename

6332762