Journal Article Large magnetocapacitance effect in magnetic tunnel junctions based on Debye-Frohlich model

Kaiju, Hideo  ,  Takei, Masashi  ,  Misawa, Takahiro  ,  Nagahama, Taro  ,  Nishii, Junji  ,  Xiao, Gang

107 ( 13 )  , pp.132405-1 - 132405-5 , 2015-09-28 , American Institute of Physics (AIP)
The frequency dependence of tunneling magnetocapacitance (TMC) in magnetic tunnel junctions (MTJs) is investigated theoretically and experimentally. According to the calculation based on Debye-Frohlich model combined with Julliere formula, the TMC ratio strongly depends on the frequency and it has the maximum peak at a specific frequency. The calculated frequency dependence of TMC is in good agreement with the experimental results obtained in MgO-based MTJs with a tunneling magnetoresistance (TMR) ratio of 108%, which exhibit a large TMC ratio of 155% at room temperature. This calculation also predicts that the TMC ratio can be as large as about 1000% for a spin polarization of 87%, while the TMR ratio is 623% for the same spin polarization. These theoretical and experimental findings provide a deeper understanding on AC spin-dependent transport in the MTJs and will open up wider opportunities for device applications, such as highly sensitive magnetic sensors and impedance-tunable devices.

Number of accesses :  

Other information