FePd₂Te₂: An Anisotropic Two-Dimensional Ferromagnet with One-Dimensional Fe Chains

Abstract

Two-dimensional (2D) magnets have attracted significant attention in recent years due to their importance in the research on both fundamental physics and spintronic applications. Here, we report the discovery of a new ternary compound FePd 2 Te 2 . It features a layered quasi-2D crystal structure with 1D Fe zigzag chains extending along the b-axis in the cleavage plane. Single crystals of FePd 2 Te 2 with centimeter size could be grown. Density functional theory calculations, mechanical exfoliation, and atomic force microscopy on these crystals reveal that they are 2D materials that can be thinned down to ∼5 nm. Magnetic characterization shows that FePd 2 Te 2 is an easy-plane ferromagnet with T C ∼ 183 K and strong in-plane uniaxial magnetic anisotropy. Magnetoresistance and the anomalous Hall effect demonstrate that ferromagnetism could be maintained in FePd 2 Te 2 flakes with large coercivity. A crystal twinning effect is observed by scanning tunneling microscopy which makes the Fe chains right angle bent in the cleavage plane and creates an intriguing spin texture. Besides, a large electronic specific heat coefficient of up to γ ∼ 32.4 mJ mol −1 K −2 suggests FePd 2 Te 2 is a strongly correlated metal. Our results show that FePd 2 Te 2 is a correlated anisotropic 2D magnet that may attract multidisciplinary research interests.