{"title":"居里温度高于400K的Cr5Te8/CrTe2异质结构中的稳健二维铁磁性。","authors":"Jielin Yang, Xinyu Wang, Shujing Li, Xina Wang*, Minghu Pan*, Mingzhong Ai, Hui Yuan, Xiaoniu Peng, Ruilong Wang, Quan Li, Fawei Zheng and Ping Zhang*, ","doi":"10.1021/acsnano.3c09654","DOIUrl":null,"url":null,"abstract":"<p >The discovery of ferromagnetism in two-dimensional (2D) van der Waals crystals has generated widespread interest. The seeking of robust 2D ferromagnets with high Curie temperature (<i>T</i><sub>c</sub>) is vitally important for next-generation spintronic devices. However, owing to the enhanced spin fluctuation and weak exchange interaction upon the reduced dimensionalities, the exploring of robust 2D ferromagnets with <i>T</i><sub>c</sub> > 300 K is highly demanded but remains challenging. In this work, we fabricated air-stable 2D Cr<sub>5</sub>Te<sub>8</sub>/CrTe<sub>2</sub> vertical heterojunctions with <i>T</i><sub>c</sub> above 400 K by the chemical vapor deposition method. Transmission electron microscopy demonstrates a high-quality-crystalline epitaxial structure between tri-Cr<sub>5</sub>Te<sub>8</sub> and 1T-CrTe<sub>2</sub> with striped moiré patterns and a superior ambient stability over six months. A built-in dual-axis strain together with strong interfacial coupling cooperatively leads to a record-high <i>T</i><sub>c</sub> for the Cr<sub><i>x</i></sub>Te<sub><i>y</i></sub> family. A temperature-dependent spin-flip process induces the easy axis of magnetization to rotate from the out-of-plane to the in-plane direction, indicating a phase-dependent proximity coupling effect, rationally interpreted by first-principles calculations of the magnetic anisotropy of a tri-Cr<sub>5</sub>Te<sub>8</sub> and 1T-CrTe<sub>2</sub> monolayer. Our results provide a material realization of effectively enhancing the transition temperature of 2D ferromagnetism and manipulating the spin-flip of the easy axis, which will facilitate future spintronic applications.</p>","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":null,"pages":null},"PeriodicalIF":15.8000,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Robust Two-Dimensional Ferromagnetism in Cr5Te8/CrTe2 Heterostructure with Curie Temperature above 400 K\",\"authors\":\"Jielin Yang, Xinyu Wang, Shujing Li, Xina Wang*, Minghu Pan*, Mingzhong Ai, Hui Yuan, Xiaoniu Peng, Ruilong Wang, Quan Li, Fawei Zheng and Ping Zhang*, \",\"doi\":\"10.1021/acsnano.3c09654\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >The discovery of ferromagnetism in two-dimensional (2D) van der Waals crystals has generated widespread interest. The seeking of robust 2D ferromagnets with high Curie temperature (<i>T</i><sub>c</sub>) is vitally important for next-generation spintronic devices. However, owing to the enhanced spin fluctuation and weak exchange interaction upon the reduced dimensionalities, the exploring of robust 2D ferromagnets with <i>T</i><sub>c</sub> > 300 K is highly demanded but remains challenging. In this work, we fabricated air-stable 2D Cr<sub>5</sub>Te<sub>8</sub>/CrTe<sub>2</sub> vertical heterojunctions with <i>T</i><sub>c</sub> above 400 K by the chemical vapor deposition method. Transmission electron microscopy demonstrates a high-quality-crystalline epitaxial structure between tri-Cr<sub>5</sub>Te<sub>8</sub> and 1T-CrTe<sub>2</sub> with striped moiré patterns and a superior ambient stability over six months. A built-in dual-axis strain together with strong interfacial coupling cooperatively leads to a record-high <i>T</i><sub>c</sub> for the Cr<sub><i>x</i></sub>Te<sub><i>y</i></sub> family. A temperature-dependent spin-flip process induces the easy axis of magnetization to rotate from the out-of-plane to the in-plane direction, indicating a phase-dependent proximity coupling effect, rationally interpreted by first-principles calculations of the magnetic anisotropy of a tri-Cr<sub>5</sub>Te<sub>8</sub> and 1T-CrTe<sub>2</sub> monolayer. Our results provide a material realization of effectively enhancing the transition temperature of 2D ferromagnetism and manipulating the spin-flip of the easy axis, which will facilitate future spintronic applications.</p>\",\"PeriodicalId\":21,\"journal\":{\"name\":\"ACS Nano\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":15.8000,\"publicationDate\":\"2023-11-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"ACS Nano\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://pubs.acs.org/doi/10.1021/acsnano.3c09654\",\"RegionNum\":1,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACS Nano","FirstCategoryId":"88","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acsnano.3c09654","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
Robust Two-Dimensional Ferromagnetism in Cr5Te8/CrTe2 Heterostructure with Curie Temperature above 400 K
The discovery of ferromagnetism in two-dimensional (2D) van der Waals crystals has generated widespread interest. The seeking of robust 2D ferromagnets with high Curie temperature (Tc) is vitally important for next-generation spintronic devices. However, owing to the enhanced spin fluctuation and weak exchange interaction upon the reduced dimensionalities, the exploring of robust 2D ferromagnets with Tc > 300 K is highly demanded but remains challenging. In this work, we fabricated air-stable 2D Cr5Te8/CrTe2 vertical heterojunctions with Tc above 400 K by the chemical vapor deposition method. Transmission electron microscopy demonstrates a high-quality-crystalline epitaxial structure between tri-Cr5Te8 and 1T-CrTe2 with striped moiré patterns and a superior ambient stability over six months. A built-in dual-axis strain together with strong interfacial coupling cooperatively leads to a record-high Tc for the CrxTey family. A temperature-dependent spin-flip process induces the easy axis of magnetization to rotate from the out-of-plane to the in-plane direction, indicating a phase-dependent proximity coupling effect, rationally interpreted by first-principles calculations of the magnetic anisotropy of a tri-Cr5Te8 and 1T-CrTe2 monolayer. Our results provide a material realization of effectively enhancing the transition temperature of 2D ferromagnetism and manipulating the spin-flip of the easy axis, which will facilitate future spintronic applications.
期刊介绍:
ACS Nano, published monthly, serves as an international forum for comprehensive articles on nanoscience and nanotechnology research at the intersections of chemistry, biology, materials science, physics, and engineering. The journal fosters communication among scientists in these communities, facilitating collaboration, new research opportunities, and advancements through discoveries. ACS Nano covers synthesis, assembly, characterization, theory, and simulation of nanostructures, nanobiotechnology, nanofabrication, methods and tools for nanoscience and nanotechnology, and self- and directed-assembly. Alongside original research articles, it offers thorough reviews, perspectives on cutting-edge research, and discussions envisioning the future of nanoscience and nanotechnology.