Title :
Enhanced Signal-to-Noise Ratio in Current-Perpendicular-to-Plane Giant-Magnetoresistance Sensors by Suppression of Spin-Torque Effects
Author :
Mihajlovic, Goran ; Nakatani, Tomoya M. ; Smith, Neil ; Read, John C. ; Young-Suk Choi ; Hsin-Wei Tseng ; Childress, Jeffrey R.
Author_Institution :
HGST, San Jose Res. Center, Western Digital Co., San Jose, CA, USA
fDate :
7/7/1905 12:00:00 AM
Abstract :
We report a ~4 dB enhancement in signal-to-noise ratio of current-perpendicular-to-the-plane giant magnetoresistance sensors with Heusler alloy magnetic layers due to insertion of an In-Zn-O electrically conductive oxide into an Ag-based metallic spacer layer. Signal and noise device characterization at various magnetic bias conditions shows that this enhancement arises from an increase in magnetoresistance signal at higher bias currents without spin-torque-induced magnetic instability. The best obtained signal-to-noise, over 30 dB for 1 GHz bandwidth, promises application of these sensors in magnetic recording heads for hard-disk drives at recording densities above 1 Tbit/in2.
Keywords :
cobalt alloys; electrical conductivity; germanium alloys; giant magnetoresistance; hard discs; iron alloys; magnetic recording; magnetic sensors; manganese alloys; Ag-based metallic spacer layer; Heusler alloy magnetic layers; Signal noise device characterization; bandwidth 1 GHz; bias currents; current-perpendicular-plane giant-magnetoresistance sensors; electrically conductive oxide; enhanced signal-noise ratio; hard-disk drives; magnetic bias conditions; magnetic recording heads; magnetoresistance signal; recording densities; spin-torque effects; spin-torque-induced magnetic instability; Giant magnetoresistance; Hard disks; Magnetic recording; Magnetic sensors; CPP-GMR; Heusler alloys; Spin electronics; giant-magnetoresistance; hard disk drives; magnetic read head; magnetic sensors; spin torque;
Journal_Title :
Magnetics Letters, IEEE
DOI :
10.1109/LMAG.2015.2496552
