Compositional Dependence of Epitaxial L10-MnxGa Magnetic Properties as Probed by 57Mn/Fe and 119In/Sn Emission Mössbauer Spectroscopy

Iraultza Unzueta; Haraldur Pall Gunnlaugsson; Torben Esmann Mølholt; Hilary Masenda; Adeleh Mokhles Gerami; Petko Krastev; Dmitry V. Zyabkin; Krish Bharuth-Ram; Deena Naidoo; Sveinn Ólafsson; Fernando Plazaola; Juliana Schell; Bingcui Qi; Xupeng Zhao; Jiaxing Xiao; Jianhua Zhao; Roberto Mantovan

doi:10.1002/pssb.202200121

Compositional Dependence of Epitaxial L1₀-Mn_xGa Magnetic Properties as Probed by ⁵⁷Mn/Fe and ¹¹⁹In/Sn Emission Mössbauer Spectroscopy

Iraultza Unzueta^*, Haraldur Pall Gunnlaugsson, Torben Esmann Mølholt, Hilary Masenda, Adeleh Mokhles Gerami, Petko Krastev, Dmitry V. Zyabkin, Krish Bharuth-Ram, Deena Naidoo, Sveinn Ólafsson, Fernando Plazaola, Juliana Schell, Bingcui Qi, Xupeng Zhao, Jiaxing Xiao, Jianhua Zhao, Roberto Mantovan

^*Corresponding author for this work

Science Institute

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

Abstract

The magnetic properties of Mn_xGa alloys critically depend on composition x, and the atomic-scale origin of those dependences is still not fully disclosed. Molecular beam epitaxy has been used to produce a set of Mn_xGa samples (x = 0.7 ÷ 1.9) with strong perpendicular magnetic anisotropy, and controllable saturation magnetization and coercive field depending on x. By conducting ⁵⁷Mn/Fe and ¹¹⁹In/Sn emission Mössbauer spectroscopy at ISOLDE/CERN, the Mn and Ga site-specific chemical, structural, and magnetic properties of Mn_xGa are investigated as a function of x, and correlated with the magnetic properties as measured by superconducting quantum interference device magnetometry. Hyperfine magnetic fields of Mn/Fe (either at Mn or Ga sites) are found to be greatly influenced by the local strain induced by the implantation. However, In/Sn probes show clear angular dependence, demonstrating a huge transferred dipolar hyperfine field to the Ga sites. A clear increase of the occupancy of Ga lattice sites by Mn for x > 1 is observed, and identified as the origin for the increased antiferromagnetic coupling between Mn and Mn at Ga sites that lowers the samples’ magnetization. The results shed further light on the atomic-scale mechanisms driving the compositional dependence of magnetism in Mn_xGa.

Original language	English
Article number	2200121
Journal	Physica Status Solidi (B) Basic Research
Volume	259
Issue number	7
DOIs	https://doi.org/10.1002/pssb.202200121
Publication status	Published - 22 May 2022

Bibliographical note

Funding Information:
The work was carried out in the framework of the experiment IS-578 at ISOLDE/CERN and financed by the European Commission through the Horizon 2020 program (grant nos. 654002 and ENSAR 2) and with the support provided by the Federal Ministry of Education and Research (BMBF) through the grant 05K16PGA. I.U. thanks GNT and acknowledges financial support by the Basque Government and Spanish Ministry of Economy and Competitiveness under grants IT-1005-16, and RTI2018-094683- B-C5 (4,5) (MCIU/AEI/FEDER, UE), respectively. D.V.Z. acknowledges the support by the German Federal Ministry of Education and Research (BMBF) project # 05K19SI. K.B.-R., H.M., and D.N. acknowledge support from the South African National Research Foundation and the Department of Science and Innovation within the SA-CERN programme. H.M. also acknowledges support from the Alexander von Humboldt (AvH) Foundation. Open Access Funding provided by Consiglio Nazionale delle Ricerche within the CRUI-CARE Agreement.

Funding Information:
The work was carried out in the framework of the experiment IS‐578 at ISOLDE/CERN and financed by the European Commission through the Horizon 2020 program (grant nos. 654002 and ENSAR 2) and with the support provided by the Federal Ministry of Education and Research (BMBF) through the grant 05K16PGA. I.U. thanks GNT and acknowledges financial support by the Basque Government and Spanish Ministry of Economy and Competitiveness under grants IT‐1005‐16, and RTI2018‐094683‐ B‐C5 (4,5) (MCIU/AEI/FEDER, UE), respectively. D.V.Z. acknowledges the support by the German Federal Ministry of Education and Research (BMBF) project # 05K19SI. K.B.‐R., H.M., and D.N. acknowledge support from the South African National Research Foundation and the Department of Science and Innovation within the SA‐CERN programme. H.M. also acknowledges support from the Alexander von Humboldt (AvH) Foundation.

Publisher Copyright:
© 2022 The Authors. physica status solidi (b) basic solid state physics published by Wiley-VCH GmbH.

Other keywords

emission Mössbauer spectroscopy
magnetism
MnGa alloys
perpendicular magnetic anisotropy

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10.1002/pssb.202200121

Cite this

Unzueta, I., Gunnlaugsson, H. P., Mølholt, T. E., Masenda, H., Mokhles Gerami, A., Krastev, P., Zyabkin, D. V., Bharuth-Ram, K., Naidoo, D., Ólafsson, S., Plazaola, F., Schell, J., Qi, B., Zhao, X., Xiao, J., Zhao, J., & Mantovan, R. (2022). Compositional Dependence of Epitaxial L1₀-Mn_xGa Magnetic Properties as Probed by ⁵⁷Mn/Fe and ¹¹⁹In/Sn Emission Mössbauer Spectroscopy. Physica Status Solidi (B) Basic Research, 259(7), Article 2200121. https://doi.org/10.1002/pssb.202200121

@article{72adae80568d422ca4e5280525b22c7c,

title = "Compositional Dependence of Epitaxial L10-MnxGa Magnetic Properties as Probed by 57Mn/Fe and 119In/Sn Emission M{\"o}ssbauer Spectroscopy",

abstract = "The magnetic properties of MnxGa alloys critically depend on composition x, and the atomic-scale origin of those dependences is still not fully disclosed. Molecular beam epitaxy has been used to produce a set of MnxGa samples (x = 0.7 ÷ 1.9) with strong perpendicular magnetic anisotropy, and controllable saturation magnetization and coercive field depending on x. By conducting 57Mn/Fe and 119In/Sn emission M{\"o}ssbauer spectroscopy at ISOLDE/CERN, the Mn and Ga site-specific chemical, structural, and magnetic properties of MnxGa are investigated as a function of x, and correlated with the magnetic properties as measured by superconducting quantum interference device magnetometry. Hyperfine magnetic fields of Mn/Fe (either at Mn or Ga sites) are found to be greatly influenced by the local strain induced by the implantation. However, In/Sn probes show clear angular dependence, demonstrating a huge transferred dipolar hyperfine field to the Ga sites. A clear increase of the occupancy of Ga lattice sites by Mn for x > 1 is observed, and identified as the origin for the increased antiferromagnetic coupling between Mn and Mn at Ga sites that lowers the samples{\textquoteright} magnetization. The results shed further light on the atomic-scale mechanisms driving the compositional dependence of magnetism in MnxGa.",

keywords = "emission M{\"o}ssbauer spectroscopy, magnetism, MnGa alloys, perpendicular magnetic anisotropy",

author = "Iraultza Unzueta and Gunnlaugsson, {Haraldur Pall} and M{\o}lholt, {Torben Esmann} and Hilary Masenda and {Mokhles Gerami}, Adeleh and Petko Krastev and Zyabkin, {Dmitry V.} and Krish Bharuth-Ram and Deena Naidoo and Sveinn {\'O}lafsson and Fernando Plazaola and Juliana Schell and Bingcui Qi and Xupeng Zhao and Jiaxing Xiao and Jianhua Zhao and Roberto Mantovan",

note = "Funding Information: The work was carried out in the framework of the experiment IS-578 at ISOLDE/CERN and financed by the European Commission through the Horizon 2020 program (grant nos. 654002 and ENSAR 2) and with the support provided by the Federal Ministry of Education and Research (BMBF) through the grant 05K16PGA. I.U. thanks GNT and acknowledges financial support by the Basque Government and Spanish Ministry of Economy and Competitiveness under grants IT-1005-16, and RTI2018-094683- B-C5 (4,5) (MCIU/AEI/FEDER, UE), respectively. D.V.Z. acknowledges the support by the German Federal Ministry of Education and Research (BMBF) project # 05K19SI. K.B.-R., H.M., and D.N. acknowledge support from the South African National Research Foundation and the Department of Science and Innovation within the SA-CERN programme. H.M. also acknowledges support from the Alexander von Humboldt (AvH) Foundation. Open Access Funding provided by Consiglio Nazionale delle Ricerche within the CRUI-CARE Agreement. Funding Information: The work was carried out in the framework of the experiment IS‐578 at ISOLDE/CERN and financed by the European Commission through the Horizon 2020 program (grant nos. 654002 and ENSAR 2) and with the support provided by the Federal Ministry of Education and Research (BMBF) through the grant 05K16PGA. I.U. thanks GNT and acknowledges financial support by the Basque Government and Spanish Ministry of Economy and Competitiveness under grants IT‐1005‐16, and RTI2018‐094683‐ B‐C5 (4,5) (MCIU/AEI/FEDER, UE), respectively. D.V.Z. acknowledges the support by the German Federal Ministry of Education and Research (BMBF) project # 05K19SI. K.B.‐R., H.M., and D.N. acknowledge support from the South African National Research Foundation and the Department of Science and Innovation within the SA‐CERN programme. H.M. also acknowledges support from the Alexander von Humboldt (AvH) Foundation. Publisher Copyright: {\textcopyright} 2022 The Authors. physica status solidi (b) basic solid state physics published by Wiley-VCH GmbH.",

year = "2022",

month = may,

day = "22",

doi = "10.1002/pssb.202200121",

language = "English",

volume = "259",

journal = "Physica Status Solidi (B) Basic Research",

issn = "0370-1972",

publisher = "Wiley-VCH Verlag",

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Unzueta, I, Gunnlaugsson, HP, Mølholt, TE, Masenda, H, Mokhles Gerami, A, Krastev, P, Zyabkin, DV, Bharuth-Ram, K, Naidoo, D, Ólafsson, S, Plazaola, F, Schell, J, Qi, B, Zhao, X, Xiao, J, Zhao, J & Mantovan, R 2022, 'Compositional Dependence of Epitaxial L1₀-Mn_xGa Magnetic Properties as Probed by ⁵⁷Mn/Fe and ¹¹⁹In/Sn Emission Mössbauer Spectroscopy', Physica Status Solidi (B) Basic Research, vol. 259, no. 7, 2200121. https://doi.org/10.1002/pssb.202200121

TY - JOUR

T1 - Compositional Dependence of Epitaxial L10-MnxGa Magnetic Properties as Probed by 57Mn/Fe and 119In/Sn Emission Mössbauer Spectroscopy

AU - Unzueta, Iraultza

AU - Gunnlaugsson, Haraldur Pall

AU - Mølholt, Torben Esmann

AU - Masenda, Hilary

AU - Mokhles Gerami, Adeleh

AU - Krastev, Petko

AU - Zyabkin, Dmitry V.

AU - Bharuth-Ram, Krish

AU - Naidoo, Deena

AU - Ólafsson, Sveinn

AU - Plazaola, Fernando

AU - Schell, Juliana

AU - Qi, Bingcui

AU - Zhao, Xupeng

AU - Xiao, Jiaxing

AU - Zhao, Jianhua

AU - Mantovan, Roberto

N1 - Funding Information: The work was carried out in the framework of the experiment IS-578 at ISOLDE/CERN and financed by the European Commission through the Horizon 2020 program (grant nos. 654002 and ENSAR 2) and with the support provided by the Federal Ministry of Education and Research (BMBF) through the grant 05K16PGA. I.U. thanks GNT and acknowledges financial support by the Basque Government and Spanish Ministry of Economy and Competitiveness under grants IT-1005-16, and RTI2018-094683- B-C5 (4,5) (MCIU/AEI/FEDER, UE), respectively. D.V.Z. acknowledges the support by the German Federal Ministry of Education and Research (BMBF) project # 05K19SI. K.B.-R., H.M., and D.N. acknowledge support from the South African National Research Foundation and the Department of Science and Innovation within the SA-CERN programme. H.M. also acknowledges support from the Alexander von Humboldt (AvH) Foundation. Open Access Funding provided by Consiglio Nazionale delle Ricerche within the CRUI-CARE Agreement. Funding Information: The work was carried out in the framework of the experiment IS‐578 at ISOLDE/CERN and financed by the European Commission through the Horizon 2020 program (grant nos. 654002 and ENSAR 2) and with the support provided by the Federal Ministry of Education and Research (BMBF) through the grant 05K16PGA. I.U. thanks GNT and acknowledges financial support by the Basque Government and Spanish Ministry of Economy and Competitiveness under grants IT‐1005‐16, and RTI2018‐094683‐ B‐C5 (4,5) (MCIU/AEI/FEDER, UE), respectively. D.V.Z. acknowledges the support by the German Federal Ministry of Education and Research (BMBF) project # 05K19SI. K.B.‐R., H.M., and D.N. acknowledge support from the South African National Research Foundation and the Department of Science and Innovation within the SA‐CERN programme. H.M. also acknowledges support from the Alexander von Humboldt (AvH) Foundation. Publisher Copyright: © 2022 The Authors. physica status solidi (b) basic solid state physics published by Wiley-VCH GmbH.

PY - 2022/5/22

Y1 - 2022/5/22

N2 - The magnetic properties of MnxGa alloys critically depend on composition x, and the atomic-scale origin of those dependences is still not fully disclosed. Molecular beam epitaxy has been used to produce a set of MnxGa samples (x = 0.7 ÷ 1.9) with strong perpendicular magnetic anisotropy, and controllable saturation magnetization and coercive field depending on x. By conducting 57Mn/Fe and 119In/Sn emission Mössbauer spectroscopy at ISOLDE/CERN, the Mn and Ga site-specific chemical, structural, and magnetic properties of MnxGa are investigated as a function of x, and correlated with the magnetic properties as measured by superconducting quantum interference device magnetometry. Hyperfine magnetic fields of Mn/Fe (either at Mn or Ga sites) are found to be greatly influenced by the local strain induced by the implantation. However, In/Sn probes show clear angular dependence, demonstrating a huge transferred dipolar hyperfine field to the Ga sites. A clear increase of the occupancy of Ga lattice sites by Mn for x > 1 is observed, and identified as the origin for the increased antiferromagnetic coupling between Mn and Mn at Ga sites that lowers the samples’ magnetization. The results shed further light on the atomic-scale mechanisms driving the compositional dependence of magnetism in MnxGa.

AB - The magnetic properties of MnxGa alloys critically depend on composition x, and the atomic-scale origin of those dependences is still not fully disclosed. Molecular beam epitaxy has been used to produce a set of MnxGa samples (x = 0.7 ÷ 1.9) with strong perpendicular magnetic anisotropy, and controllable saturation magnetization and coercive field depending on x. By conducting 57Mn/Fe and 119In/Sn emission Mössbauer spectroscopy at ISOLDE/CERN, the Mn and Ga site-specific chemical, structural, and magnetic properties of MnxGa are investigated as a function of x, and correlated with the magnetic properties as measured by superconducting quantum interference device magnetometry. Hyperfine magnetic fields of Mn/Fe (either at Mn or Ga sites) are found to be greatly influenced by the local strain induced by the implantation. However, In/Sn probes show clear angular dependence, demonstrating a huge transferred dipolar hyperfine field to the Ga sites. A clear increase of the occupancy of Ga lattice sites by Mn for x > 1 is observed, and identified as the origin for the increased antiferromagnetic coupling between Mn and Mn at Ga sites that lowers the samples’ magnetization. The results shed further light on the atomic-scale mechanisms driving the compositional dependence of magnetism in MnxGa.

KW - emission Mössbauer spectroscopy

KW - magnetism

KW - MnGa alloys

KW - perpendicular magnetic anisotropy

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DO - 10.1002/pssb.202200121

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JO - Physica Status Solidi (B) Basic Research

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