Two-Dimensional Wedge-Shaped Magnetic EuS: Insight into the Substrate Step-Guided Epitaxial Synthesis on Sapphire
Author(s): Zhang, B (Zhang, Biao); Yun, C (Yun, Chao); Wu, H (Wu, Heng); Zhao, ZJ (Zhao, Zijing); Zeng, Y (Zeng, Yi); Liang, D (Liang, Dong); Shen, T (Shen, Tong); Zhang, JE (Zhang, Jine); Huang, XX (Huang, Xiaoxiao); Song, JP (Song, Jiepeng); Xu, JJ (Xu, Junjie); Zhang, Q (Zhang, Qing); Tan, PH (Tan, Ping-Heng); Gao, S (Gao, Song); Hou, YL (Hou, Yanglong)
Source: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY DOI: 10.1021/jacs.2c06023 Early Access Date: OCT 2022
Abstract: Rare earth chalcogenides (RECs) with novel luminescence and magnetic properties offer fascinating oppor-tunities for fundamental research and applications. However, controllable synthesis of RECs down to the two-dimensional (2D) limit still has a great challenge. Herein, 2D wedge-shaped ferromagnetic EuS single crystals are successfully synthesized via a facile molten-salt-assisted chemical vapor deposition method on sapphire. Based on the theoretical simulations and experimental measurements, the mechanisms of aligned growth and wedge-shaped growth are systematically proposed. The wedge-shaped growth is driven by a dual-interaction mechanism, where the coupling between EuS and the substrate steps impedes the lateral growth, and the strong bonding of nonlayered EuS itself facilitates the vertical growth. Through temperature-dependent Raman and photoluminescence characterization, the nanoflakes show a large Raman temperature coefficient of -0.030 cm-1 K-1 and uncommon increasing band gap with temperature. More importantly, by low-temperature magnetic force microscopy characterization, thickness variation of the magnetic signal is revealed within one sample, indicating the great potential of the wedge-shaped nanoflake to serve as a platform for highly efficient investigation of thickness-dependent magnetic properties. This work sheds new light on 2D RECs and will offer a deep understanding of 2D wedge-shaped materials.
Accession Number: WOS:000874634700001
PubMed ID: 36257067
Author Identifiers:
Author Web of Science ResearcherID ORCID Number
TAN, Ping-Heng D-1137-2009 0000-0001-6575-1516
ISSN: 0002-7863
eISSN: 1520-5126
