Covalent mixing in the two-dimensional ferromagnet CrSiTe₃ evidenced by magnetic x-ray circular dichroism
<p>The low-temperature electronic structure of the van der Waals ferromagnet CrSiTe3 has been investigated. This ferromagnetic semiconductor has a magnetic bulk transition temperature of 33 K, which can reach up to 80 K in single- and few-layer flakes. X-ray absorption spectroscopy (XAS) and x...
| Main Authors: | , , , , , , |
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| Format: | Journal article |
| Language: | English |
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Wiley
2021
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| _version_ | 1826307941602426880 |
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| author | Achinuq, B Fujita, R Xia, W Guo, Y Bencok, P van der Laan, G Hesjedal, T |
| author_facet | Achinuq, B Fujita, R Xia, W Guo, Y Bencok, P van der Laan, G Hesjedal, T |
| author_sort | Achinuq, B |
| collection | OXFORD |
| description | <p>The low-temperature electronic structure of the van der Waals ferromagnet CrSiTe3 has been investigated. This ferromagnetic semiconductor has a magnetic bulk transition temperature of 33 K, which can reach up to 80 K in single- and few-layer flakes. X-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) measurements, carried out at the Cr <em>L</em><sub>2,3</sub> and Te <em>M</em><sub>b</sub> edges on in vacuo cleaved single crystals, give strong evidence for hybridization-mediated super-exchange between the Cr atoms. The observed chemical shift in the XAS, as well as the comparison of the XMCD with the calculated Cr L<sub>2,3</sub> multiplet spectra, confirm a strongly covalent bond between the Cr <em>3d</em>(<em>e</em><sub>g</sub>) and Te 5<em>p</em> states. Application of the XMCD sum rules gives a non-vanishing orbital moment, supporting a partial occupation of the <em>e<sub>g</sub></em> states, apart from the <em>t</em><sub>2<em>g</em></sub>. Also, the presence of a non-zero XMCD signal at the Te Mb edge confirms a Te 5<em>p</em> spin polarization due to mixing with the Cr <em>e<sub>g</sub></em> bonding states. The results strongly suggest that superexchange, instead of the previously suggested single ion anisotropy, is responsible for the low-temperature ferromagnetic ordering of 2D materials such as CrSiTe<sub>3</sub> and CrGeTe<sub>3</sub>. This demonstrates the interplay between electron correlation and ferromagnetism in insulating two-dimensional materials.</p> |
| first_indexed | 2024-03-07T07:10:43Z |
| format | Journal article |
| id | oxford-uuid:5f2eaf0e-d2fa-49ae-9bfe-1e2f320dd530 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:10:43Z |
| publishDate | 2021 |
| publisher | Wiley |
| record_format | dspace |
| spelling | oxford-uuid:5f2eaf0e-d2fa-49ae-9bfe-1e2f320dd5302022-06-22T11:53:08ZCovalent mixing in the two-dimensional ferromagnet CrSiTe₃ evidenced by magnetic x-ray circular dichroismJournal articlehttp://purl.org/coar/resource_type/c_545buuid:5f2eaf0e-d2fa-49ae-9bfe-1e2f320dd530EnglishSymplectic ElementsWiley2021Achinuq, BFujita, RXia, WGuo, YBencok, Pvan der Laan, GHesjedal, T<p>The low-temperature electronic structure of the van der Waals ferromagnet CrSiTe3 has been investigated. This ferromagnetic semiconductor has a magnetic bulk transition temperature of 33 K, which can reach up to 80 K in single- and few-layer flakes. X-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) measurements, carried out at the Cr <em>L</em><sub>2,3</sub> and Te <em>M</em><sub>b</sub> edges on in vacuo cleaved single crystals, give strong evidence for hybridization-mediated super-exchange between the Cr atoms. The observed chemical shift in the XAS, as well as the comparison of the XMCD with the calculated Cr L<sub>2,3</sub> multiplet spectra, confirm a strongly covalent bond between the Cr <em>3d</em>(<em>e</em><sub>g</sub>) and Te 5<em>p</em> states. Application of the XMCD sum rules gives a non-vanishing orbital moment, supporting a partial occupation of the <em>e<sub>g</sub></em> states, apart from the <em>t</em><sub>2<em>g</em></sub>. Also, the presence of a non-zero XMCD signal at the Te Mb edge confirms a Te 5<em>p</em> spin polarization due to mixing with the Cr <em>e<sub>g</sub></em> bonding states. The results strongly suggest that superexchange, instead of the previously suggested single ion anisotropy, is responsible for the low-temperature ferromagnetic ordering of 2D materials such as CrSiTe<sub>3</sub> and CrGeTe<sub>3</sub>. This demonstrates the interplay between electron correlation and ferromagnetism in insulating two-dimensional materials.</p> |
| spellingShingle | Achinuq, B Fujita, R Xia, W Guo, Y Bencok, P van der Laan, G Hesjedal, T Covalent mixing in the two-dimensional ferromagnet CrSiTe₃ evidenced by magnetic x-ray circular dichroism |
| title | Covalent mixing in the two-dimensional ferromagnet CrSiTe₃ evidenced by magnetic x-ray circular dichroism |
| title_full | Covalent mixing in the two-dimensional ferromagnet CrSiTe₃ evidenced by magnetic x-ray circular dichroism |
| title_fullStr | Covalent mixing in the two-dimensional ferromagnet CrSiTe₃ evidenced by magnetic x-ray circular dichroism |
| title_full_unstemmed | Covalent mixing in the two-dimensional ferromagnet CrSiTe₃ evidenced by magnetic x-ray circular dichroism |
| title_short | Covalent mixing in the two-dimensional ferromagnet CrSiTe₃ evidenced by magnetic x-ray circular dichroism |
| title_sort | covalent mixing in the two dimensional ferromagnet crsite₃ evidenced by magnetic x ray circular dichroism |
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