Title :
High Spin-Torque Diode Sensitivity in CoFeB/MgO/CoFeB Magnetic Tunnel Junctions Under DC Bias Currents
Author :
Ishibashi, Shojiro ; Ando, K. ; Seki, Takaya ; Nozaki, Takayuki ; Kubota, Hajime ; Yakata, S. ; Maehara, Hiroaki ; Fukushima, Akio ; Yuasa, Shinji ; Suzuki, Yuya
Author_Institution :
Grad. Sch. of Eng. Sci., Osaka Univ., Toyonaka, Japan
Abstract :
We report a large enhancement of spin-torque diode sensitivity in CoFeB/MgO/CoFeB magnetic tunnel junctions measured under perpendicular magnetic fields and dc bias currents. In the measurement of homodyne detection, a large dc output voltage of 190 μV was obtained when an RF signal power of -30 dB ·m and a dc current of +1.0 mA were applied. This value corresponds to the diode sensitivity of 190 mV/mW (260 mV/mW after impedance matching correction). The main origin of this enhancement is an offset of the damping torque and an increase in the precession angle induced by the spin-transfer torque due to the dc bias current application.
Keywords :
boron alloys; cobalt alloys; iron alloys; magnesium compounds; magnetic multilayers; magnetic tunnelling; magnetoresistance; CoFeB-MgO-CoFeB; damping torque; dc bias current; magnetic field; magnetic tunnel junctions; multilayers; spin-torque diode sensitivity; spin-transfer torque; Junctions; Magnetic multilayers; Magnetic resonance; Magnetic tunneling; Radio frequency; Sensitivity; Torque; Magnetoresistance effect; MgO-based magnetic tunnel junctions (MTJs); spin-torque diode effect; spin-torque diode sensitivity;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2011.2159830
