Direct observation of spin polarization in epitaxial Fe3O4(001)/MgO thin films grown by magnetron sputtering

Zhe Zhang; Xianyang Lu; Yu Yan; Jiahua Lu; Zhuoyi Li; Qi Liu; Fangyuan Zhu; Jiefeng Cao; Yong Wang; Ya Zhai; Yao Li; Xuezhong Ruan; Liang He; Jing Wu; Jun Du; Rong Zhang; Yongbing Xu

doi:10.1063/5.0091241

Direct observation of spin polarization in epitaxial Fe₃O₄(001)/MgO thin films grown by magnetron sputtering

Zhe Zhang, Xianyang Lu, Yu Yan, Jiahua Lu, Zhuoyi Li, Qi Liu, Fangyuan Zhu, Jiefeng Cao, Yong Wang, Ya Zhai, Yao Li, Xuezhong Ruan, Liang He, Jing Wu, Jun Du, Rong Zhang, Yongbing Xu^*

^*Corresponding author for this work

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

Abstract

We obtained epitaxial single-crystal Fe3O4(001)/MgO(001) thin films by magnetron sputtering. The high quality of the grown Fe3O4 films was confirmed by reflection high-energy electron diffraction and x-ray photoelectron spectroscopy. Atomic magnetic properties of Fe3O4(001)/MgO(001) were investigated using vibrating sample magnetometry and x-ray magnetic circular dichroism. The values of saturation magnetization and magnetic moment are 407 ± 5 emu/cm3 (3.26 ± 0.04 μ B / (f. u.)) and 3.31 ± 0.15 μ B / (f. u.), respectively, in the Fe3O4 film as thin as 5 nm, which are close to the bulk values. The spin polarization was directly measured using spin-resolved photoemission spectroscopy. The measured spin polarization has a maximum value of -42% ± 3%, which is comparable to the theoretical value for the (2 × 2)R45° reconstructed Fe3O4(001) surface. Furthermore, the film thickness-dependent measurements indicate that the anti-phase boundaries significantly decrease the spin polarization rather than the lattice mismatch. Our results demonstrate that epitaxial Fe3O4(001)/MgO thin films grown by magnetron sputtering have desired magnetic properties, facilitating the potential application of Fe3O4-based spintronic devices.

Original language	English
Article number	182403
Number of pages	7
Journal	Applied Physics Letters
Volume	120
Issue number	18
DOIs	https://doi.org/10.1063/5.0091241
Publication status	Published - 3 May 2022

Bibliographical note

Funding Information:
This work was supported by the National Key Research and Development Program of China (Grant No. 2021YFB3601600), the National Natural Science Foundation of China (Grant Nos. 12104216 and 61427812), and the Natural Science Foundation of Jiangsu Province of China (Nos. BK20200307, BK20192006, and BK20180056). The authors would like to thank the staff at BL07U beamline of the Shanghai Synchrotron Radiation Facility (SSRF) for assistance with XMCD/XAS data collection.

© 2022 Author(s). This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details

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10.1063/5.0091241

2022 APL22-AR-01977
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Cite this

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title = "Direct observation of spin polarization in epitaxial Fe3O4(001)/MgO thin films grown by magnetron sputtering",

abstract = "We obtained epitaxial single-crystal Fe3O4(001)/MgO(001) thin films by magnetron sputtering. The high quality of the grown Fe3O4 films was confirmed by reflection high-energy electron diffraction and x-ray photoelectron spectroscopy. Atomic magnetic properties of Fe3O4(001)/MgO(001) were investigated using vibrating sample magnetometry and x-ray magnetic circular dichroism. The values of saturation magnetization and magnetic moment are 407 ± 5 emu/cm3 (3.26 ± 0.04 μ B / (f. u.)) and 3.31 ± 0.15 μ B / (f. u.), respectively, in the Fe3O4 film as thin as 5 nm, which are close to the bulk values. The spin polarization was directly measured using spin-resolved photoemission spectroscopy. The measured spin polarization has a maximum value of -42% ± 3%, which is comparable to the theoretical value for the (2 × 2)R45° reconstructed Fe3O4(001) surface. Furthermore, the film thickness-dependent measurements indicate that the anti-phase boundaries significantly decrease the spin polarization rather than the lattice mismatch. Our results demonstrate that epitaxial Fe3O4(001)/MgO thin films grown by magnetron sputtering have desired magnetic properties, facilitating the potential application of Fe3O4-based spintronic devices. ",

author = "Zhe Zhang and Xianyang Lu and Yu Yan and Jiahua Lu and Zhuoyi Li and Qi Liu and Fangyuan Zhu and Jiefeng Cao and Yong Wang and Ya Zhai and Yao Li and Xuezhong Ruan and Liang He and Jing Wu and Jun Du and Rong Zhang and Yongbing Xu",

note = "Funding Information: This work was supported by the National Key Research and Development Program of China (Grant No. 2021YFB3601600), the National Natural Science Foundation of China (Grant Nos. 12104216 and 61427812), and the Natural Science Foundation of Jiangsu Province of China (Nos. BK20200307, BK20192006, and BK20180056). The authors would like to thank the staff at BL07U beamline of the Shanghai Synchrotron Radiation Facility (SSRF) for assistance with XMCD/XAS data collection. {\textcopyright} 2022 Author(s). This is an author-produced version of the published paper. Uploaded in accordance with the publisher{\textquoteright}s self-archiving policy. Further copying may not be permitted; contact the publisher for details ",

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month = may,

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doi = "10.1063/5.0091241",

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volume = "120",

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TY - JOUR

T1 - Direct observation of spin polarization in epitaxial Fe3O4(001)/MgO thin films grown by magnetron sputtering

AU - Zhang, Zhe

AU - Lu, Xianyang

AU - Yan, Yu

AU - Lu, Jiahua

AU - Li, Zhuoyi

AU - Liu, Qi

AU - Zhu, Fangyuan

AU - Cao, Jiefeng

AU - Wang, Yong

AU - Zhai, Ya

AU - Li, Yao

AU - Ruan, Xuezhong

AU - He, Liang

AU - Wu, Jing

AU - Du, Jun

AU - Zhang, Rong

AU - Xu, Yongbing

N1 - Funding Information: This work was supported by the National Key Research and Development Program of China (Grant No. 2021YFB3601600), the National Natural Science Foundation of China (Grant Nos. 12104216 and 61427812), and the Natural Science Foundation of Jiangsu Province of China (Nos. BK20200307, BK20192006, and BK20180056). The authors would like to thank the staff at BL07U beamline of the Shanghai Synchrotron Radiation Facility (SSRF) for assistance with XMCD/XAS data collection. © 2022 Author(s). This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details

PY - 2022/5/3

Y1 - 2022/5/3

N2 - We obtained epitaxial single-crystal Fe3O4(001)/MgO(001) thin films by magnetron sputtering. The high quality of the grown Fe3O4 films was confirmed by reflection high-energy electron diffraction and x-ray photoelectron spectroscopy. Atomic magnetic properties of Fe3O4(001)/MgO(001) were investigated using vibrating sample magnetometry and x-ray magnetic circular dichroism. The values of saturation magnetization and magnetic moment are 407 ± 5 emu/cm3 (3.26 ± 0.04 μ B / (f. u.)) and 3.31 ± 0.15 μ B / (f. u.), respectively, in the Fe3O4 film as thin as 5 nm, which are close to the bulk values. The spin polarization was directly measured using spin-resolved photoemission spectroscopy. The measured spin polarization has a maximum value of -42% ± 3%, which is comparable to the theoretical value for the (2 × 2)R45° reconstructed Fe3O4(001) surface. Furthermore, the film thickness-dependent measurements indicate that the anti-phase boundaries significantly decrease the spin polarization rather than the lattice mismatch. Our results demonstrate that epitaxial Fe3O4(001)/MgO thin films grown by magnetron sputtering have desired magnetic properties, facilitating the potential application of Fe3O4-based spintronic devices.

AB - We obtained epitaxial single-crystal Fe3O4(001)/MgO(001) thin films by magnetron sputtering. The high quality of the grown Fe3O4 films was confirmed by reflection high-energy electron diffraction and x-ray photoelectron spectroscopy. Atomic magnetic properties of Fe3O4(001)/MgO(001) were investigated using vibrating sample magnetometry and x-ray magnetic circular dichroism. The values of saturation magnetization and magnetic moment are 407 ± 5 emu/cm3 (3.26 ± 0.04 μ B / (f. u.)) and 3.31 ± 0.15 μ B / (f. u.), respectively, in the Fe3O4 film as thin as 5 nm, which are close to the bulk values. The spin polarization was directly measured using spin-resolved photoemission spectroscopy. The measured spin polarization has a maximum value of -42% ± 3%, which is comparable to the theoretical value for the (2 × 2)R45° reconstructed Fe3O4(001) surface. Furthermore, the film thickness-dependent measurements indicate that the anti-phase boundaries significantly decrease the spin polarization rather than the lattice mismatch. Our results demonstrate that epitaxial Fe3O4(001)/MgO thin films grown by magnetron sputtering have desired magnetic properties, facilitating the potential application of Fe3O4-based spintronic devices.

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DO - 10.1063/5.0091241

M3 - Article

AN - SCOPUS:85129884855

SN - 0003-6951

VL - 120

JO - Applied Physics Letters

JF - Applied Physics Letters

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