Influence of frequency and DC bias on magnetoimpedance behaviors in doubleMgO magnetic tunnel junctions
Abstract
Magnetoimpedance (MI) of a doublebarrier MgO magnetic tunnel junction (DMTJ) is measured as a function of frequency (20 Hz3 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 frequencydc bias ( fV) "phase diagram" is mapped out to describe the combination effects of the magnetoimpedance response. The decay of the tunnel magnetoresistance (TMR) and tunnel magnetocapacitance (TMC) at high voltage is sufficiently reduced by the doubleMgO 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.
 Publication:

Solid State Communications
 Pub Date:
 October 2010
 DOI:
 10.1016/j.ssc.2010.06.008
 Bibcode:
 2010SSCom.150.1856K