Room Temperature Ferromagnetism of Monolayer Chromium Telluride with Perpendicular Magnetic Anisotropy

• Published in: Advanced materials (Weinheim) Vol. 33; no. 42; pp. e2103360 - n/a
• Main Authors: Chua, Rebekah, Zhou, Jun, Yu, Xiaojiang, Yu, Wei, Gou, Jian, Zhu, Rui, Zhang, Lei, Liu, Meizhuang, Breese, Mark B. H., Chen, Wei, Loh, Kian Ping, Feng, Yuan Ping, Yang, Ming, Huang, Yu Li, Wee, Andrew T. S.
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.10.2021
• Subjects: 2D magnets; Chromium; CMOS; Coupling (molecular); Curie temperature; Density functional theory; Dichroism; Epitaxial growth; Ferromagnetism; Magnetic anisotropy; Magnetism; Materials science; Molecular beam epitaxy; monolayer chromium telluride; Monolayers; Room temperature; room temperature ferromagnetism; scanning tunneling microscopy; Temperature; Thickness; X‐ray magnetic circular dichroism
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202103360

The realization of long‐range magnetic ordering in 2D systems can potentially revolutionize next‐generation information technology. Here, the successful fabrication of crystalline Cr3Te4 monolayers with room temperature (RT) ferromagnetism is reported. Using molecular beam epitaxy, the growth of 2D Cr3Te4 films with monolayer thickness is demonstrated at low substrate temperatures (≈100 °C), compatible with Si complementary metal oxide semiconductor technology. X‐ray magnetic circular dichroism measurements reveal a Curie temperature (Tc) of v344 K for the Cr3Te4 monolayer with an out‐of‐plane magnetic easy axis, which decreases to v240 K for the thicker film (≈7 nm) with an in‐plane easy axis. The enhancement of ferromagnetic coupling and the magnetic anisotropy transition is ascribed to interfacial effects, in particular the orbital overlap at the monolayer Cr3Te4/graphite interface, supported by density‐functional theory calculations. This work sheds light on the low‐temperature scalable growth of 2D nonlayered materials with RT ferromagnetism for new magnetic and spintronic devices. The room‐temperature ferromagnetism of monolayer Cr3Te4, which is not an inherently layered material, is reported. Molecular beam epitaxy allows the successful growth of 2D Cr3Te4 in the monolayer form on graphite at low substrate temperatures, e.g., ≈100 °C, which is compatible with Si complementary metal–oxide–semiconductor technology.