Near Degeneracy of Magnetic Phases in Two-Dimensional Chromium Telluride with Enhanced Perpendicular Magnetic Anisotropy

• Published in: ACS nano Vol. 14; no. 11; pp. 15256 - 15266
• Main Authors: Coughlin, Amanda L, Xie, Dongyue, Yao, Yue, Zhan, Xun, Chen, Qiang, Hewa-Walpitage, Heshan, Zhang, Xiaohang, Guo, Hua, Zhou, Haidong, Lou, Jun, Wang, Jian, Li, Yan S, Fertig, Herbert A, Zhang, Shixiong
• Format: Journal Article
• Language: English
• Published: American Chemical Society 24.11.2020
• Subjects: chromium telluride; canted ferromagnetic order; 2D magnets; perpendicular magnetic anisotropy; phase degeneracy
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/acsnano.0c05534

The discovery of atomically thin van der Waals magnets (e.g., CrI3 and Cr2Ge2Te6) has triggered a renaissance in the study of two-dimensional (2D) magnetism. Most of the 2D magnetic compounds discovered so far host only one single magnetic phase unless the system is at a phase boundary. In this work, we report the near degeneracy of magnetic phases in ultrathin chromium telluride (Cr2Te3) layers with strong perpendicular magnetic anisotropy highly desired for stabilizing 2D magnetic order. Single-crystalline Cr2Te3 nanoplates with a trigonal structure (space group P3̅1c) were grown by chemical vapor deposition. The bulk magnetization measurements suggest a ferromagnetic (FM) order with an enhanced perpendicular magnetic anisotropy, as evidenced by a coercive field as large as ∼14 kOe when the field is applied perpendicular to the basal plane of the thin nanoplates. Magneto-optical Kerr effect studies confirm the intrinsic ferromagnetism and characterize the magnetic ordering temperature of individual nanoplates. First-principles density functional theory calculations suggest the near degeneracy of magnetic orderings with a continuously varying canting from the c-axis FM due to their comparable energy scales, explaining the zero-field kink observed in the magnetic hysteresis loops. Our work highlights Cr2Te3 as a promising 2D Ising system to study magnetic phase coexistence and switches for ultracompact information storage and processing.