Large exchange bias induced by polycrystalline Mn3Ga antiferromagnetic films with controlled layer thickness

Haokaifeng Wu; Iori Sudoh; Ruihan Xu; Wenshuo Si; Carlos Vaz; Jun-Young Kim; Gonzalo Vallejo Fernandez; Atsufumi Hirohata

doi:10.1088/1361-6463/aabd8e

Large exchange bias induced by polycrystalline Mn3Ga antiferromagnetic films with controlled layer thickness

Haokaifeng Wu, Iori Sudoh, Ruihan Xu, Wenshuo Si, Carlos Vaz, Jun-Young Kim, Gonzalo Vallejo Fernandez, Atsufumi Hirohata

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

Abstract

Polycrystalline Mn3Ga layers with thickness in the range from 6-20 nm were deposited at room temperature by a high target utilisation sputtering. To investigate the onset of exchange-bias, a ferromagnetic Co0.6Fe0.4 layer (3.3-9 nm thick) capped with 5 nm Ta, were subsequently deposited. X-ray diffraction measurements confirm the presence of Mn3Ga (0002) and (0004) peaks characteristic of the D019 antiferromagnetic structure. The 6 nm thick Mn3Ga film shows the largest exchange bias of 430 Oe at 120 K with a blocking temperature of 225 K. The blocking temperature is found to decrease with increasing Mn3Ga thickness. These results in combination with X-ray reflectivity measurements confirm that the quality of the Mn3Ga/Co0.6Fe0.4 interface controls the exchange bias, with the sharp interface with the 6-nm-thick Mn3Ga inducing the largest exchange bias. The magneto-crystalline anisotropy for 6 nm thick Mn3Ga thin film sample is calculated to be 9×10^4 J/m^3. Such a binary antiferromagnetic Heusler alloy is compatible with the current memory fabrication process and hence has a great potential for antiferromagnetic spintronics.

Original language	English
Article number	215003
Number of pages	8
Journal	Journal of Physics D: Applied Physics
Volume	51
DOIs	https://doi.org/10.1088/1361-6463/aabd8e
Publication status	Published - 12 Apr 2018

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@article{8673d9666ca548cbaea5a616299dd586,

title = "Large exchange bias induced by polycrystalline Mn3Ga antiferromagnetic films with controlled layer thickness",

abstract = "Polycrystalline Mn3Ga layers with thickness in the range from 6-20 nm were deposited at room temperature by a high target utilisation sputtering. To investigate the onset of exchange-bias, a ferromagnetic Co0.6Fe0.4 layer (3.3-9 nm thick) capped with 5 nm Ta, were subsequently deposited. X-ray diffraction measurements confirm the presence of Mn3Ga (0002) and (0004) peaks characteristic of the D019 antiferromagnetic structure. The 6 nm thick Mn3Ga film shows the largest exchange bias of 430 Oe at 120 K with a blocking temperature of 225 K. The blocking temperature is found to decrease with increasing Mn3Ga thickness. These results in combination with X-ray reflectivity measurements confirm that the quality of the Mn3Ga/Co0.6Fe0.4 interface controls the exchange bias, with the sharp interface with the 6-nm-thick Mn3Ga inducing the largest exchange bias. The magneto-crystalline anisotropy for 6 nm thick Mn3Ga thin film sample is calculated to be 9×10^4 J/m^3. Such a binary antiferromagnetic Heusler alloy is compatible with the current memory fabrication process and hence has a great potential for antiferromagnetic spintronics.",

author = "Haokaifeng Wu and Iori Sudoh and Ruihan Xu and Wenshuo Si and Carlos Vaz and Jun-Young Kim and {Vallejo Fernandez}, Gonzalo and Atsufumi Hirohata",

note = "{\textcopyright} 2018 IOP Publishing Ltd.",

year = "2018",

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doi = "10.1088/1361-6463/aabd8e",

language = "English",

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TY - JOUR

T1 - Large exchange bias induced by polycrystalline Mn3Ga antiferromagnetic films with controlled layer thickness

AU - Wu, Haokaifeng

AU - Sudoh, Iori

AU - Xu, Ruihan

AU - Si, Wenshuo

AU - Vaz, Carlos

AU - Kim, Jun-Young

AU - Vallejo Fernandez, Gonzalo

AU - Hirohata, Atsufumi

PY - 2018/4/12

Y1 - 2018/4/12

N2 - Polycrystalline Mn3Ga layers with thickness in the range from 6-20 nm were deposited at room temperature by a high target utilisation sputtering. To investigate the onset of exchange-bias, a ferromagnetic Co0.6Fe0.4 layer (3.3-9 nm thick) capped with 5 nm Ta, were subsequently deposited. X-ray diffraction measurements confirm the presence of Mn3Ga (0002) and (0004) peaks characteristic of the D019 antiferromagnetic structure. The 6 nm thick Mn3Ga film shows the largest exchange bias of 430 Oe at 120 K with a blocking temperature of 225 K. The blocking temperature is found to decrease with increasing Mn3Ga thickness. These results in combination with X-ray reflectivity measurements confirm that the quality of the Mn3Ga/Co0.6Fe0.4 interface controls the exchange bias, with the sharp interface with the 6-nm-thick Mn3Ga inducing the largest exchange bias. The magneto-crystalline anisotropy for 6 nm thick Mn3Ga thin film sample is calculated to be 9×10^4 J/m^3. Such a binary antiferromagnetic Heusler alloy is compatible with the current memory fabrication process and hence has a great potential for antiferromagnetic spintronics.

AB - Polycrystalline Mn3Ga layers with thickness in the range from 6-20 nm were deposited at room temperature by a high target utilisation sputtering. To investigate the onset of exchange-bias, a ferromagnetic Co0.6Fe0.4 layer (3.3-9 nm thick) capped with 5 nm Ta, were subsequently deposited. X-ray diffraction measurements confirm the presence of Mn3Ga (0002) and (0004) peaks characteristic of the D019 antiferromagnetic structure. The 6 nm thick Mn3Ga film shows the largest exchange bias of 430 Oe at 120 K with a blocking temperature of 225 K. The blocking temperature is found to decrease with increasing Mn3Ga thickness. These results in combination with X-ray reflectivity measurements confirm that the quality of the Mn3Ga/Co0.6Fe0.4 interface controls the exchange bias, with the sharp interface with the 6-nm-thick Mn3Ga inducing the largest exchange bias. The magneto-crystalline anisotropy for 6 nm thick Mn3Ga thin film sample is calculated to be 9×10^4 J/m^3. Such a binary antiferromagnetic Heusler alloy is compatible with the current memory fabrication process and hence has a great potential for antiferromagnetic spintronics.

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DO - 10.1088/1361-6463/aabd8e

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JO - Journal of Physics D: Applied Physics

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