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

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

doi:10.1063/1.4932093

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

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

Research output: Contribution to journal › Article › peer-review

19 Citations (Scopus)

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-Fröhlich 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.

Original language	English
Article number	132405
Journal	Applied Physics Letters
Volume	107
Issue number	13
DOIs	https://doi.org/10.1063/1.4932093
Publication status	Published - 2015 Sept 28
Externally published	Yes

ASJC Scopus subject areas

Physics and Astronomy (miscellaneous)

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title = "Large magnetocapacitance effect in magnetic tunnel junctions based on Debye-Fr{\"o}hlich model",

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-Fr{\"o}hlich 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.",

author = "Hideo Kaiju and Masashi Takei and Takahiro Misawa and Taro Nagahama and Junji Nishii and Gang Xiao",

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T1 - Large magnetocapacitance effect in magnetic tunnel junctions based on Debye-Fröhlich model

AU - Kaiju, Hideo

AU - Takei, Masashi

AU - Misawa, Takahiro

AU - Nagahama, Taro

AU - Nishii, Junji

AU - Xiao, Gang

PY - 2015/9/28

Y1 - 2015/9/28

N2 - The frequency dependence of tunneling magnetocapacitance (TMC) in magnetic tunnel junctions (MTJs) is investigated theoretically and experimentally. According to the calculation based on Debye-Fröhlich 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.

AB - The frequency dependence of tunneling magnetocapacitance (TMC) in magnetic tunnel junctions (MTJs) is investigated theoretically and experimentally. According to the calculation based on Debye-Fröhlich 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.

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

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