Room Temperature Ferromagnetism of Monolayer Chromium Telluride with Perpendicular Magnetic Anisotropy.

Chua, Rebekah; Zhou, Jun; Yu, Xiaojiang; Yu, Wei; Gou, Jian; Zhu, Rui; Zhang, Lei; Liu, Meizhuang et al. · Adv Mater · 2021

basic_science · Level V

Where this comes from

Abstract

The realization of long-range magnetic ordering in 2D systems can potentially revolutionize next-generation information technology. Here, the successful fabrication of crystalline Cr<sub>3</sub> Te<sub>4</sub> monolayers with room temperature (RT) ferromagnetism is reported. Using molecular beam epitaxy, the growth of 2D Cr<sub>3</sub> Te<sub>4</sub> 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 (T<sub>c</sub> ) of v344 K for the Cr<sub>3</sub> Te<sub>4</sub> 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 Cr<sub>3</sub> Te<sub>4</sub> /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.