The two-dimensional (2D) van der Waals (vdW) material CrCl3 is an A-type antiferromagnet with in-plane magnetic anisotropy. It is a promising material for exploring strain and doping control of magnetic states and constructing novel spintronic devices. Achieving controlled synthesis of high-quality, scalable CrCl3 samples is critical for its technological applications, while growth of large scale, ultrathin samples remains challenging.
This talk focuses on synthesizing atomic-thick CrCl3 flakes and investigating their magnetic properties through transport measurements. Utilizing the physical vapor transport (PVT) technique, ultrathin CrCl3 flakes are successfully synthesized. High-resolution transmission electron microscopy and confocal Raman measurements show the samples possess high crystallinity with monoclinic structure. The sample morphology and ambient stability are investigated using atomic force microscopy. We fabricate graphite/few-layer CrCl3/graphite tunnel junctions. Tunneling magnetoresistance measurements on these devices show that few-layer CrCl3 exhibits in-plane magnetic anisotropy and a Néel temperature of 17 K. We also explore the ferroelectric field effect modulation of CrCl3 tunnel junctions top-gated by a PbZr0.2Ti0.8O3 (PZT) membrane. Switching the polarization of the PZT top layer enables nonvolatile modulation of the tunneling current and induces a metal-insulator transition in CrCl3.
Our results present a direct growth method for synthesizing ultrathin 2D CrCl3 flakes and highlight the potential for designing antiferromagnetic spintronic devices and integrating 2D magnets with ferroelectric materials.