Author(s): Zeng, Y (Zeng, Yi); Gu, PF (Gu, Pingfan); Zhao, ZJ (Zhao, Zijing); Zhang, BA (Zhang, Biao); Lin, ZC (Lin, Zhongchong); Peng, YX (Peng, Yuxuan); Li, W (Li, Wei); Zhao, WT (Zhao, Wanting); Leng, YC (Leng, Yuchen); Tan, PH (Tan, Pingheng); Yang, T (Yang, Teng); Zhang, ZD (Zhang, Zhidong); Song, YT (Song, Youting); Yang, JB (Yang, Jinbo); Ye, Y (Ye, Yu); Tian, KS (Tian, Kesong); Hou, YL (Hou, Yanglong)

Source: ADVANCED MATERIALS Article Number: 2108847 DOI: 10.1002/adma.202108847 Early Access Date: FEB 2022

Abstract: 2D van der Waals (vdW) transition-metal oxyhalides with low symmetry, novel magnetism, and good stability provide a versatile platform for conducting fundamental research and developing spintronics. Antiferromagnetic FeOCl has attracted significant interest owing to its unique semiconductor properties and relatively high Neel temperature. Herein, good-quality centimeter-scale FeOCl single crystals are controllably synthesized using the universal temperature-oscillation chemical vapor transport (TO-CVT) method. The crystal structure, bandgap, and anisotropic behavior of the 2D FeOCl are explored in detail. The absorption spectrum and electrical measurements reveal that 2D FeOCl is a semiconductor with an optical bandgap of approximate to 2.1 eV and a resistivity of approximate to 10(-1) omega m at 295 K, and the bandgap increases with decreasing thickness. Strong in-plane optical and electrical anisotropies are observed in 2D FeOCl flakes, and the maximum resistance anisotropic ratio reaches 2.66 at 295 K. Additionally, the lattice vibration modes are studied through temperature-dependent Raman spectra and first-principles density functional calculations. A significant decrease in the Raman frequencies below the Neel temperature is observed, which results from the strong spin-phonon coupling effect in 2D FeOCl. This study provides a high-quality low-symmetry vdW magnetic candidate for miniaturized spintronics.

Accession Number: WOS:000760266300001

PubMed ID: 35102635

Author Identifiers:

Author Web of Science ResearcherID ORCID Number

TAN, Ping-Heng D-1137-2009 0000-0001-6575-1516

ISSN: 0935-9648

eISSN: 1521-4095

Full Text: https://onlinelibrary.wiley.com/doi/10.1002/adma.202108847