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

• Kaiju, Hideo

• Takei, Masashi

• Misawa, Takahiro

• Nagahama, Taro

• Nishii, Junji

• Xiao, Gang

Abstract

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.

Journal

• Applied physics letters

  Applied physics letters 107 (13), 132405-1-132405-5, 2015-09-28

  American Institute of Physics (AIP)

Details

• CRID: 1050845763949427584
• NII Article ID: 120005670605
• HANDLE: 2115/60214
• ISSN: 00036951
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles