2017年以来发现的Cr2X2Te6(X=Ge,Si)、CrI3和FeAY3(A=S,Se)等二维van der Waals(2D vdW)磁性绝缘材料，其自旋波的低能磁激发中存在着各向异性的能隙，磁的各项异性抵消了热涨落对于长程磁有序的限制，能带具有较大能隙，是自旋电子学领域有应用潜力的新型材料。FePA3具有反铁磁性，高压下结构发生塌缩、磁性相伴消失、并逐步出现绝缘体-金属-超导相变。Cr2X2Te6和CrI3为铁磁有序，但与FePA3有着许多共同的特征：层间为van der Waals相互作用、层内由共价键结合、近正八面体结构单元、六角蜂窝状结构、3d4-3d7型过渡金属磁性离子以及由于Hund定则耦合而产生的绝缘电性。此类材料性质在压力下具有丰富的变化。本项目将对2D vdW铁磁性绝缘材料Cr2X2Te6和CrI3开展高压下的结构、电性和磁性研究，从而更好的理解该系列材料的性质。

The recently discovered two-dimensional van der Waals (2D vdW) materials such as Cr2X2Te6（X=Ge，Si）, CrI3 and FePA3（A=S，Se）exhibit magnetic anisotropy, which could stabilize a long-range magnetic order by opening up an excitation gap to resist the thermal agitation. Their band structure also has a large energy gap, hence these 2D vdW insulators have been viewed as potential materials for future electronics, including spintronics. FePA3 are anti-ferromagnetic. Cr2X2Te6 and CrI3 are ferromagnetic. Under pressure, FePA3 undergo large in-plane lattice collapses, abrupt spin-crossovers, magnetic moment vanishings, and insulator-metal-superconductivity transitions. Except magnetic order, Cr2X2Te6 and CrI3 share many common features with FePA3 such as van der Waals interaction between layers, the covalent bond in the layer, quasi-octahedral structural units, hexagonal honeycomb lattice, 3d4-3d7 transition metal ions and insulation electrical properties due to the strong correlations from Hund’s coupling. These features show fetal changes under pressure. This project will focus on the evolutions of the structures, electricity properties, and magnetic properties under pressure for the 2D vdW ferromagnetic insulators Cr2X2Te6 and CrI3.