Raman Spectroscopy Of Two-Dimensional Magnetic CuCrP₂S₆

Magnetism in lower dimensions hosts interesting physics that has been studied theoretically for many decades.However,experimentally realizing the details of these theoretical predictions has been proven difficult.The reason for this difficulty is that atomically thin yet stable films are hard to obtain.The isolation of monolayer graphene by mechanical exfoliation provided a path for exploring magnetism in two-dimensional van der Waals materials.New research shows that magnetic ordering was observed in FePS₃,Cr₂GeTe₆,CrI₃,VSe₂ and Fe₃GeTe₂.In CuCrP₂S₆,there may be multiferroics since the coexistence of Cu+site-based dipole ordering.Those two-dimensional magnetic materials can be used to build nanoscale spintronics devices with a very large tunneling magnetoresistance.Our research focuses on the characterization of two-dimensional CuCrP₂S₆nanosheets with different thickness by Raman spectroscopy,so that the thickness dependence and temperature dependence of their structure can be studied.The main contents of this research are listed below:?1?The structure of CuCrP₂S₆ crystal and its resulted magnetic and electronic phase transitions are introduced.?2?CuCrP₂S₆ single crystals are synthesized by chemical vapor transport.The structure and compositions of the CuCrP₂S₆ single crystal are characterized by X-ray diffraction?XRD?and Energy Dispersive X-Ray Spectroscopy?EDX?.?3?CuCrP₂S₆ nanosheets with different thickness are exfoliated on silicon substrate.Their thicknesses are determined by optical contrast and Atomic Force Microscopy?AFM?.?4?Ambient instability of few-layer CuCrP₂S₆ are confirmed by Atomic Force Microscopy?AFM?and Raman spectroscopy.?5?A series of variable temperature dependent Raman spectra is taken from few-layer CuCrP₂S₆ with different thickness.The temperature of the structural phase transition in few-layer CuCrP₂S₆ is determined.