Hard ferromagnetic van-der-Waals metal (Fe,Co)3GeTe2: a new platform for the study of low-dimensional magnetic quantum criticality
Autor: | Kaixuan Zhang, Youngtek Oh, Suhan Son, Inho Hwang, Insu Jeon, Dong-Su Ko, Jung-Hyun Kim, Nahyun Lee, Matthew J. Coak, Je-Geun Park |
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Rok vydání: | 2019 |
Předmět: |
Materials science
Condensed matter physics Dopant Magnetism Transition temperature 02 engineering and technology Coercivity 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Condensed Matter::Materials Science symbols.namesake Ferromagnetism Quantum critical point 0103 physical sciences symbols Curie temperature General Materials Science van der Waals force 010306 general physics 0210 nano-technology |
Zdroj: | Journal of Physics: Condensed Matter. 31:50LT01 |
ISSN: | 1361-648X 0953-8984 |
Popis: | The widely-studied ferromagnetic van-der-Waals (vdW) metal Fe3GeTe2 has great promise for studies of quantum criticality in the 2D limit, but is limited by a relatively high Curie temperature in excess of 200 K. To help render the quantum critical point achievable in such a system within the reach of practically possible tuning methods, we have grown single crystals of a variant of (Fe,Co)3GeTe2 with useful physical properties for both this purpose and the wider study of low-dimensional magnetism and spin transport. (Fe,Co)3GeTe2 is found through x-ray diffraction and electron microscopy to have an equivalent crystal structure to Fe3GeTe2, with a random distribution of the cobalt dopant sites. It exhibits a sharp ferromagnetic transition at a value below 40 K, a stronger anisotropy and a coercive field ten times larger than that of Fe3GeTe2. The transport properties and specific heat show the electronic properties and strong correlations of Fe3GeTe2 to be near-unchanged in this doped material. We demonstrate that (Fe,Co)3GeTe2 can be cleanly exfoliated down to monolayer thickness. This unprecedented hard metallic vdW ferromagnet is a valuable new addition to the limited range of materials available for the study of 2D magnetism. |
Databáze: | OpenAIRE |
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