Influence of frequency and DC bias on magneto-impedance behaviors in double-MgO magnetic tunnel junctions

✍ Scribed by K.M. Kuo; C.Y. Lin; C.T. Lin; G. Chern; C.T. Chao; Lance Horng; J.C. Wu; Teho Wu; C.Y. Huang; H. Ohyama; S. Isogami; M. Tsunoda; M. Takahashi

• Book ID: 104093873
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 545 KB
• Volume: 150
• Category: Article
• ISSN: 0038-1098
• DOI: 10.1016/j.ssc.2010.06.008

✦ Synopsis

Magneto-impedance (MI) of a double-barrier MgO magnetic tunnel junction (DMTJ) is measured as a function of frequency (20 Hz-3 MHz) and DC bias (-1 to 1 V) under magnetic parallel and antiparallel states. A strong nonlinear effect is observed at all frequencies and the MI changes from positive to negative at the relaxation frequency ∼1/RC. A frequency-dc bias (f -V ) ''phase diagram'' is mapped out to describe the combination effects of the magneto-impedance response. The decay of the tunnel magneto-resistance (TMR) and tunnel magneto-capacitance (TMC) at high voltage is sufficiently reduced by the double-MgO barrier. The V 1/2 (the voltage that magnetic response drops to 1/2 of its maximum) of TMC reaches an average value of ∼1.35 V, which is larger than the V 1/2 of TMR ∼0.95 V, suggesting that the response of TMC is more stable than TMR for high frequency application.