Tuning the Room Temperature Ferromagnetism in Fe5GeTe2 by Arsenic Substitution
| Autor: | May, Andrew F., Yan, Jiaqiang, Hermann, Raphael, Du, Mao-Hua, McGuire, Michael A. |
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| Rok vydání: | 2021 |
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| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/2053-1583/ac34d9 |
| Popis: | In order to tune the magnetic properties of the cleavable high-Curie temperature ferromagnet Fe$_{5-x}$GeTe$_2$, the effect of increasing the electron count through arsenic substitution has been investigated. Small additions of arsenic (2.5 and 5%) seemingly enhance ferromagnetic order in polycrystalline samples by quenching fluctuations on one of the three magnetic sublattices, whereas larger As concentrations decrease the ferromagnetic Curie temperature ($T_{\rm C}$) and saturation magnetization. This work also describes the growth and characterization of Fe$_{4.8}$AsTe$_2$ single crystals that are structurally analogous to Fe$_{5-x}$GeTe$_2$ but with some phase stability complications. Magnetization measurements reveal dominant antiferromagnetic behavior in Fe$_{4.8}$AsTe$_2$ with a N\'{e}el temperature of $T_{\rm N}$ $\approx$42K. A field-induced spin-flop below $T_{\rm N}$ results in a switch from negative to positive magnetoresistance, with significant hysteresis causing butterfly-shaped resistance loops. In addition to reporting the properties of Fe$_{4.8}$AsTe$_2$, this work shows the importance of manipulating the individual magnetic sublattices in Fe$_{5-x}$GeTe$_2$ and motivates further efforts to control the magnetic properties in related materials by fine tuning of the Fermi energy or crystal chemistry. Comment: Accepted for publication in 2D Materials, with accepted version online |
| Databáze: | arXiv |
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