Diverse Structures and Magnetic Properties in Nonlayered Monolayer Chromium Selenide

• Published in: The journal of physical chemistry letters 2021-08, Vol.12 (32), p.7752-7760
• Main Authors: Liu, Meizhuang, Huang, Yu Li, Gou, Jian, Liang, Qijie, Chua, Rebekah, Arramel, Duan, Sisheng, Zhang, Lei, Cai, LiangLiang, Yu, Xiaojiang, Zhong, Dingyong, Zhang, Wenjing, Wee, Andrew T. S
• Format: Article
• Language: English
• Subjects: Physical Insights into Materials and Molecular Properties
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.1c01493

Thickness-dependent magnetic behavior has previously been observed in chemical vapor deposition-grown chromium selenide. However, the low-dimensional structure in nonlayered chromium selenide, which plays a crucial role in determining the low-dimensional magnetic order, needs further study. Here, we report the structure-dependent magnetic properties in monolayer CrSe2 and Cr2Se3 grown by molecular beam epitaxy. In the monolayer CrSe2, 1T-CrSe2 with a lattice constant of 3.3 Å has a metallic character, coexisting with the 1T″ phase with 2 × 2 surface periodicity. Monolayer CrSe2 can be transformed into Cr2Se3 with a lattice constant of 3.6 Å by annealing at 300 °C. X-ray magnetic circular dichroism (XMCD) measurements combined with DFT calculations reveal that while the MBE-grown monolayer CrSe2 is antiferromagnetic, monolayer Cr2Se3 is ferromagnetic with a Curie temperature of ∼200 K. This work demonstrates the structural diversity in nonlayered chromium selenide and the critical effect of different structures on its electronic and magnetic properties.