二维磁性材料 VX3与 MnIn2Se4的磁光拉曼研究

二维磁性材料的出现为凝聚态物理开辟了新的领域，为探究低维磁性理论 提供了理想的平台。 VX3 与 MnIn2Se4 材料是具有代表意义的两类二维磁性材 料，其潜在的物理图像为未来自旋电子器件等领域奠定坚实的基础。 拉曼光谱作为一种具有对微小扰动高度敏感的无损测量技术， 是表征二维磁性材料的结构与振动物理特性的理想工具。 拉曼散射光谱对晶格对称性的高灵敏性可以揭示二维磁性材料的磁序、相变和自旋-声子耦合等。 自二维磁性材料发现以来，常用的拉曼光谱只作为探测磁性的间接证据，直接探测磁性的拉曼手段还未完全找到。 近年来， 在二维磁性材料 CrI3 中观测到的磁光拉曼效应表明磁序会极大的影响声子的散射特性， 这预示着利用拉曼光谱直接探测磁性成为可能。然而，二维磁性材料的磁序调控非弹性散射光的机理依然不清楚。 另一方面， 许多本征二维磁性材料有待发现，其结构和磁学的相关物理特性有待解决。 这些问题的研究能为磁序与光相互作用的机理和探讨新兴二维磁性理论提供参考，并为未来自旋电子器件的开发设计和应用提供潜在方向。本文系统研究了二维磁性材料VX3与MnIn2Se4的磁光拉曼效应。首先利用化学气相传输方法成功生长了高质量VI3、 VBr3与MnIn2Se4单晶，然后使用干法转移技术将对空气敏感的VI3和VBr3样品通过上下两层六方氮化硼形成类似三明治结构进行封装保护，进而用于拉曼光谱的测量。主要研究工作概述如下：
（ 1） 对VI3进行了系统的拉曼光谱分析，探讨存在争议的VI3的结构， 并进一步探索磁激发、耦合等磁光效应。 结果表明：通过变温和偏振拉曼谱发现VI3会在温度降低到80 K时发生结构相变，从 C2 m 相转变到 R3相； 同时发现，材料的磁能量涨落过程引起了准弹性散射现象，且磁涨落与声子强烈耦合，产生Fano反共振现象。 另外，还测到VI3材料中单磁振子和双磁振子模式，这是二维磁性材料很少见的，并结合理论计算得到了VI3材料的磁各向异性和层内交换耦合强度。 更重要是，通过圆偏振拉曼的手段，测试了VI3材料的旋光性。发现磁序可以极大地影响VI3中光学声子的拉曼散射特性， 使VI3材料对左右圆偏振光的散射强度不同，这直接反映了材料的时间反演对称性破缺。 随后首次对声子圆偏振拉曼选择定则进行了群论的理论分析。 Ag声子模式随温度和外磁场变化的圆偏振光谱，出现的旋光现象可以清楚地探测出VI3的铁磁性与磁滞行为。所以， 圆偏振拉曼光谱为直接探测其他二维铁磁材料的磁性提供了重要手段。
（ 2）系统研究了二维磁性材料VBr3的结构和磁性。结果表明：通过单晶X射线衍射(SC-XRD)与X射线能量色谱(EDS)证明了生长出高质量的VBr3样品；变温X射线衍射谱(XRD)揭示了材料在90 K时发生结构相变；然后， 通过系统的拉曼光谱，发现131 cm-1为中心的双简并Eg模式将在低温相分裂为Ag+Bg模式。这对应结构相变过程中的三重旋转对称性破缺， 即随温度的降低从 R3转变为 C2 m 相；变温拉曼光谱还观测到磁能量密度涨落的准弹性散射信号。同时，比热和磁化率测量也证实了VBr3在90 K附近发生结构相变，并在26.5 K以下温区进入反铁磁有序态。有意思的是当磁场平行于晶格c轴，外加磁场小于0.5 T时， 磁化率-温度依赖曲线表现出多畴的铁磁特征。此外，等温磁化曲线也观测到大的铁磁回滞， 2 K时矫顽场约为1.5 T。值得注意的是整个磁化曲线存在一个明显的反铁磁线性背底，因而铁磁磁滞也是倾斜的。当磁场平行于ab面时却没有明显的铁磁磁滞。结合面内和面外转交磁化率测量， 可以认为VBr3的磁基态应该是倾斜的反铁磁。
（ 3） 在上述卤素二元磁性材料研究的基础上， 开展了三元化合物磁性材料MnIn2Se4的结构与磁性的研究。 结果表明：利用XRD、 EDS、磁化率等手段表征了材料的晶体质量与磁性，证明了成功生长出高质量的MnIn2Se4材料，其在3.5 K以下是反铁磁相互作用的自旋玻璃态。然后对MnIn2Se4进行系统的拉曼研究，并结合第一性原理计算，确定了此材料室温拉曼振动模式。变温拉曼实验结果说明材料在180 K存在结构相变。通过变温-偏振拉曼实验对准弹性散射拉曼峰与两个磁连续态拉曼峰的偏振性研究，发现两者都在180 K发生转变，进一步确定了材料的结构相变温度。实验也观测到MnIn2Se4材料中准弹性散射与声子的耦合现象。 最后用层数依赖拉曼光谱证明了准弹性散射随层间相互作用力增加而增大， 10 层以下的拉曼光谱27 cm-1的声子峰随层数增加发生蓝移，178 cm-1声子峰随层数增加发生红移，因此，可以通过拉曼位移确定材料的层数变化。

The emergence of two-dimensional magnetic materials opens up a new field for condensed matter physics and provides an ideal platform for exploring the low dimensional magnetic theory. VX3 and MnIn2Se4 materials are two types representative two-dimensional magnetic materials. Their potential surprising physical images will be laid a solid foundation for future electronic spin devices fields. As a non-destructive measurement technology with micron spatial resolution, Raman spectroscopy is an ideal tool to characterize the physical properties of two-dimensional materials, such as structure and phonon vibration. Due to its high spatial resolution and high sensitivity to lattice symmetry, Raman spectroscopy can reveal the magnetic order, phase transition and spin phonon coupling of two-dimensional magnets. Since the discovery of two-dimensional magnetic materials, the commonly used Raman spectra have only been used as indirect evidence for detecting magnetism, and the Raman methods for directly detecting magnetism has not been fully found. In recent years, the magnetooptical Raman effect observed in the two-dimensional magnetic material CrI3 indicates that the magnetic order will greatly affect the scattering of phonons, which indicates that it is possible to directly detect magnetism using Raman spectroscopy. However, the mechanism of inelastic scattering light controlled by the magnetic order of two-dimensional magnetic materials is still unclear. On the other hand, many intrinsic two-dimensional magnetic materials need to be discovered, and their physical properties related to structure and magnetism need to be solved. These studies will provide a reference for the mechanism of the interaction between magnetic order and light, and reference for the discussion of the emerging two-dimensional magnetic theory, which affords a potential direction for the development and application of spin electronic devices in the future.
In this thesis, the magneto-optical Raman effect of two-dimensional magnetic materials VX3 and MnIn2Se4 have been studied systematically. High-quality VI3, VBr3 and MnIn2Se4 single crystals were successfully grown by chemical vapor transport method, and the air sensitive VI3 and VBr3 samples were encapsulated by hexagonal boron nitride thin layers which like sandwich structure using dry transfer technology for Raman measurement. The main research results are summarized as follows:
(1) The structure, magnetic excitation and coupling of the two-dimensional magnetic material VI3 were explored through the systematic Raman spectra. From the temperature dependent and polarized Raman spectroscopy, the results show that the structure of VI3 changes from C2 m phase to R3 phase with the decrease of temperature; We also measured the quasi-elastic scattering which representing the magnetic fluctuation. Interestingly, we found that it was strongly coupled with the adjacent phonon modes, emerging a Fano anti-resonance phenomenon.
Besides the lattice excitations, single magnon and two magnon modes are measured at low temperature. Those modes are rare in two-dimensional magnetic materials. Then, the magnetic anisotropy and intralayer exchange coupling strength are estimated by combining the density function theory and the linear spin wave theory. More importantly, we measured the ferromagnetism of VI3 samples by helicity resolved Raman spectroscopy. It is proved that the magnetic order can greatly affect the Raman scattering characteristics of photons in VI3, which is consistent with the breaking of time reversal symmetry in the material. The selection rule of Ag mode of circularly polarized Raman is theoretically analyzed by group theory. The helicity resolved Raman spectra of the main Ag modes with temperature-dependent and magnetic field dependent clearly show the ferromagnetism in VI3. The helicity resolved Raman spectroscopy are directly used to detect the magnetic phase transition in two-dimensional ferromagnetism;
(2) The structure and magnetism of two-dimensional magnetic material VBr3 were systematically studied. Single crystal X-ray diffraction (SC-XRD) and Xray energy chromatography (EDS) proved that high quality VBr3 samples were grown. The temperature-dependent XRD spectra revealed that the structural phase transition occurred at 90 K; Through systematic Raman spectra, it is found that Eg mode centered at 131 cm-1 will split into Ag+Bg mode at low temperature. It is
proved that the triple rotational symmetry is broken after structural phase transition, the VBr3 structure changes from R3 phase to C2 m phase with the decrease of temperature; The quasi-elastic scattering signal from the fluctuation of magnetic energy density was also measured by temperature-dependent Raman spectroscopy. The magnetism of the material was determined by the measure of magnetic susceptibility and specific heat. The measurements confirmed that VBr3
undergoes a structural phase transition near 90 K and enters an antiferromagnetic ordered state below 26.5 K. Interestingly, when the magnetic field is parallel to the c-axis of the lattice and the applied magnetic field is less than 0.5 T, the susceptibility temperature dependent curve shows the ferromagnetic characteristics of multiple domains. In addition, a large ferromagnetic hysteresis is also observed in the isothermal magnetization curve, and the coercive field is about 1.5 T at 2 K. It is worth noting that there is an obvious antiferromagnetic background in the whole magnetization curve, so the ferromagnetic hysteresis is also inclined. When the magnetic field is parallel to the ab plane, there is no obvious ferromagnetic hysteresis. Combined with in-plane and out of plane angle dependent susceptibility measurements, it can be considered that the magnetic ground state of VBr3 should be canted anti-ferromagnetism.
(3) Basis of the above researches on halogen binary magnetic materials, we further carried out the research on the structure and magnetic properties of ternary two-dimensional magnetic material MnIn2Se4. Firstly, the crystal quality and magnetism of the material were determined by X-ray diffraction, X-ray electron spectroscopy, magnetic susceptibility. It is proved that high-quality MnIn2Se4 material has spin glass state under antiferromagnetic interaction below 3.5 K. Secondly, the Raman spectra of MnIn2Se4 were systematically measured, and the Raman vibration mode of this material was determined by combining the first principal calculation. The results of temperature dependent Raman measurements show that there is a structural phase transition at 180 K. The polarization of the quasi-elastic scattering and the two magnetic continuous were studied by the temperature dependent polarized Raman measurement. It is found that both of them changes at 180 K, which further determines the structural phase transition temperature of the MnIn2Se4 material. The quasi-elastic scattering and phonon mode are coupled to produce the Fano resonance phenomenon. The layer dependent Raman spectrum proves that the quasi-elastic scattering increases with the increase of the interlayer interaction force. For the Raman spectrum below 10 layers, the phonon peak of 27 cm-1 blue shifts with the increase of the layer number, and the phonon peak of 178 cm-1 red shifts with the increase of the layer number. Therefore, the layer number change of the material can be determined by the Raman shift.
 

[1] Novoselov K. S G, A. K, Morozov S. V, et al., Electric field effect in atomically thin carbon films[J], Science, 2004,306(22):666-669.
[2] Ma Y, Dai, Y., Guo, M., et al., Electronic and magnetic properties of perfect, vacancy-doped, and nonmetal adsorbed MoSe2, MoTe2 and WS2 monolayers[J], Physical Chemistry Chemical Physics, 2011,13(34):15546-15553.
[3] Saito R, Hofmann M, Dresselhaus G, et al., Raman spectroscopy of graphene and carbon nanotubes[J], Advances in Physics, 2011,60(3):413-550.
[4] Crassee I, Levallois J, Walter A L, et al., Giant faraday rotation in single- and multilayer graphene[J], Nature Physics, 2010,7(1):48-51.
[5] Zhu J, Christensen J, Jung J, et al., A holey-structured metamaterial for acoustic deep-subwavelength imaging[J], Nature Physics, 2010,7(1):52-55.
[6] Mak K F, Shan J, Heinz T F, Seeing many-body effects in single- and fewlayer graphene: observation of two-dimensional saddle-point excitons[J], Physical Review Letters, 2011,106(4):046401.
[7] Radisavljevic B, Radenovic A, Brivio J, et al., Single-layer MoS2 transistors[J], Nature Nanotechnology, 2011,6(3):147-150.
[8] Geim A K, Grigorieva I V, Vander Waals heterostructures[J], Nature, 2013,499(7459):419-425.
[9] Fu S, Kang K, Shayan K, et al., Enabling room temperature ferromagnetism in monolayer MoS2 via in-situ iron-doping[J], Nature Communications, 2020,11(1):2034.
[10] Wang H, Huang X, Lin J, et al., High-quality monolayer superconductor NbSe2 grown by chemical vapour deposition[J], Nature Communications, 2017,8(1):394.
[11] Kim J, Kim K W, Shin D, et al., Prediction of ferroelectricity-driven berry curvature enabling charge- and spin-controllable photocurrent in tin telluride monolayers[J], Nature Communications, 2019,10(1):3965.
[12] Koppens F H, Mueller T, Avouris P, et al., Photodetectors based on graphene, other two-dimensional materials and hybrid systems[J], Nature Nanotechnology, 2014,9(10):780-793.
[13] Liu X, Galfsky T S, Zheng X, et al., Strong light–matter coupling in two dimensional atomic crystals[J], Nature Photonics, 2014,9(1):30-34.
[14] Cepellotti A F, Paulatto L, Lazzeri M, et al., Phonon hydrodynamics in two dimensional materials[J], Nature Communications, 2015,6(6400):1-7.
[15] Yang X, Zhang X, Deng J, et al., Efficient green light-emitting diodes based on quasi-two-dimensional composition and phase engineered perovskite with surface passivation[J], Nature Communications, 2018,9(1):570.
[16] Allain A, Kang J, Banerjee K, et al., Electrical contacts to two-dimensional semiconductors[J], Nature Materials, 2015,14(12):1195-1205.
[17] Ozeki Y, Umemura W, Otsuka Y, et al., High-speed molecular spectral imaging of tissue with stimulated Raman scattering[J], Nature Photonics, 2012,6(12):845-851.
[18] Xu X, Pereira L F, Wang Y, et al., Length-dependent thermal conductivity in suspended single-layer graphene[J], Nature Communications, 2014,5(3689):1-6.
[19] Shimon K, Ania C, Bleszynski J, et al., Coherent sensing of a mechanical resonator with a single-spin qubit[J], Science, 2012,335(30):1603-1606.
[20] Li B, Huang L, Zhong M, et al., Synthesis and transport properties of largescale alloy Co0.16Mo0.84S2 bilayer nanosheets[J], ACS nano, 2015,9(2):1257–1262.
[21] Zhang K, Feng S, Wang J, et al., Manganese doping of monolayer MoS2: the substrate is critical[J], Nano Letters, 2015,15(10):6586-6591.
[22] Ryee S, Yoon H, Kim T J, et al., Induced magnetic two-dimensionality by hole doping in the superconducting infinite-layer nickelate Nd1−xSrxNiO2[J], Physical Review B, 2020,101(6):0645131-0645135.
[23] Mishra R, Zhou W, Pennycook S J, et al., Long-range ferromagnetic ordering in manganese-doped two-dimensional dichalcogenides[J], Physical Review B, 2013,88(14):1444091-1444095.
[24] Gong C, Li L, Li Z, et al., Discovery of intrinsic ferromagnetism in two dimensional van der Waals crystals[J], Nature, 2017,546(7657):265-269.
[25] Huang B, Clark G, Navarro-Moratalla E, et al., Layer-dependent ferromagnetism in a van der Waals crystal down to the monolayer limit[J], Nature, 2017,546(7657):270-273.
[26] Sun Z, Yi Y, Song T, et al., Giant nonreciprocal second-harmonic generation from antiferromagnetic bilayer CrI3[J], Nature, 2019,572(7770):497-501.
[27] Huang B, Clark G, Klein D R, et al., Electrical control of 2D magnetism in bilayer CrI3[J], Nature Nanotechnology, 2018,13(7):544-548.
[28] Burch K S, Mandrus D, Park J G, Magnetism in two-dimensional van der Waals materials[J], Nature, 2018,563(7729):47-52.
[29] Gong C, Zhang X, Two-dimensional magnetic crystals and emergent heterostructure devices[J], Science, 2019,363(6428):1-11.
[30] Kim H H, Yang B, Li S, et al., Evolution of interlayer and intralayer magnetism in three atomically thin chromium trihalides[J], Proceedings of the National Academy of Sciences, 2019,116(23):11131-11136.
[31] Mak K F, Shan J, Ralph D C, Probing and controlling magnetic states in 2D layered magnetic materials[J], Nature Reviews Physics, 2019,1(11), 646-661.
[32] Jiang S, Li L, Wang Z, et al., Controlling magnetism in 2D CrI3 by electrostatic doping[J], Nature Nanotechnology, 2018,13(7):549-553.
[33] Zhang J, Zhao B, Zhou T, et al., Strong magnetization and Chern insulators in compressed graphene/CrI3 van der Waals heterostructures[J], Physical Review B, 2018,97(8):085401.
[34] Chen L, Chung J-H, Gao B, et al., Topological Spin Excitations in Honeycomb Ferromagnet CrI3[J], Physical Review X, 2018,8(4):041028.
[35] Jiang S, Li L, Wang Z, et al., Spin tunnel field-effect transistors based on two-dimensional van der Waals heterostructures[J], Nature Electronics, 2019,2(4):159-163.
[36] Jiang S, Shan J, Mak K F, Electric-field switching of two-dimensional van der Waals magnets[J], Nature Materials, 2018,17(5):406-410.
[37] Yekta Y, Hadipour H, Şaşıoğlu E, et al., Strength of effective Coulomb interaction in two-dimensional transition-metal halides MX2 and MX3 (M=Ti, V, Cr, Mn, Fe, Co, Ni; X=Cl, Br, I)[J], Physical Review Materials, 2021,5(3):0340011-03400110.
[38] Mcguire M, Crystal and magnetic structures in layered, transition metal dihalides and trihalides[J], Crystals, 2017,7(5):121-146.
[39] Ferrari A C, Meyer, J. C, Scardaci, V, et al. Raman spectrum of graphene and graphene layers[J], Physical Review Letters, 2006,97(18):187401.
[40] Ferrari A C, Basko D M, Raman spectroscopy as a versatile tool for studying the properties of graphene[J], Nature Nanotechnology, 2013,8(4):235-246.
[41] Papasimakis N, Mailis S, Huang C C, et al., Strain engineering in graphene by laser irradiation[J], Applied Physics Letters, 2015,106(6):0619041-0619044.
[42] Mueller N S, Heeg S, Alvarez M P, et al., Evaluating arbitrary strain configurations and doping in graphene with Raman spectroscopy[J], 2D Materials, 2017,5(1):0150161-01501610.
[43] Song S, Keum D H, Cho S, et al., Room temperature semiconductor-metal transition of MoTe2 thin films engineered by strain[J], Nano Letters, 2016,16(1):188-193.
[4
[44] Zhang B, Cai, C, Zhu, H, et al., Phonon blocking by two dimensional electrongas in polar CdTe/PbTe heterojunctions[J], Applied Physics Letters, 2014,104(16):161601
[45] Chen S Y, Zheng C, Fuhrer M S, et al., Helicity-resolved Raman scattering of MoS2, MoSe2, WS2, and WSe2 atomic layers[J], Nano Letters, 2015,15(4):2526-2532.
[46] Lee J U, Lee S, Ryoo J H, et al., Ising-type magnetic ordering in atomically thin FePS3[J], Nano Letters, 2016,16(12):7433-7438.
[47] Long G, Zhang T, Cai X, et al., Isolation and characterization of few-layer manganese thiophosphite[J], ACS nano, 2017,11(11):11330-11336.
[48] Wang Y M, Zhang J F, Li C H, et al., Raman scattering study of magnetic layered MPS3 crystals (M=Mn, Fe, Ni)[J], Chinese Physics B, 2019,28(5):056301.
[49] Jin W, Kim H H, Ye Z, et al., Raman fingerprint of two terahertz spin wave branches in a two-dimensional honeycomb Ising ferromagnet[J], Nature Communications, 2018,9(1):5122.
[50] Kandus A, Kunze Kerstin E, Tsagas C G., Primordial magnetogenesis[J], Physics Reports, 2011,505(1):1-58.
[51] Parker E N, The origin of magnetic fields[J], The Astrophysical Journal, 1970,160(2):383-404.
[52] Subramanian K, The origin, evolution and signatures of primordial magnetic fields[J], Report Progress Physics, 2016,79(7):076901.
[53] Wang B M, Liu Y, Ren P, et al., Large exchange bias after zero-field cooling from an unmagnetized state[J], Physical Review Letters, 2011,106(7):077203.
[54] Wu F, Yang K, Li Q, et al., Biomass-derived 3D magnetic porous carbon fibers with a helical/chiral structure toward superior microwave absorption[J], Carbon, 2021,173(8):918-931.
[55] Lu P, Wu X, Guo W, et al., Strain-dependent electronic and magnetic properties of MoS2 monolayer, bilayer, nanoribbons and nanotubes[J], Physical Chemistry Chemical Physics, 2012,14(37):13035-13040.
[56] Kim Y, Yuk H, Zhao R, et al , Printing ferromagnetic domains for untethered fast-transforming soft materials[J], Nature, 2018,558(7709):274-279.
[57] Zhao B, Li Y, Zeng Q, et al., Galvanic replacement reaction involving core shell magnetic chains and orientation-tunable microwave absorption properties[J], Small, 2020,16(40):e2003502.
[58] Pontin D I, Three-dimensional magnetic reconnection regimes: A review[J], Advances in Space Research, 2011,47(9):1508-1522.
[59] Mermin N D, Wagner H., Absence of ferromagnetism or antiferromagnetism in one- or two-dimensional isotropic heisenberg models[J], Physical Review Letters, 1966,17(22):1133-1136.
[60] Hohenberg P C, Existence of Long-range order in one and two dimensions[J],Physical Review, 1967,158(2):383-386.
[61] Elliott R J, Loudon R, The possible observation of electronic Raman transition in crystals[J], Physics Letters, 1963,3(4):189-191.
[62] Fei Z, Huang B, Malinowski P, et al., Two-dimensional itinerant ferromagnetism in atomically thin Fe3GeTe2[J], Nature Materials, 2018,17(9):778-782.
[63] Blei M, Lado J L, Song Q, et al., Synthesis, engineering, and theory of 2D van der Waals magnets[J], Applied Physics Reviews, 2021,8(2):021301.
[64] Wei S, Liao X, Wang C, et al., Emerging intrinsic magnetism in twodimensional materials: theory and applications[J], 2D Materials, 2020,8(1):012005.
[65] Lado J L, Fernández-Rossier J, On the origin of magnetic anisotropy in two dimensional CrI3[J], 2D Materials, 2017,4(3):035002.
[66] Torelli D, Thygesen K S, Olsen T, High throughput computational screening for 2D ferromagnetic materials: the critical role of anisotropy and local correlations[J], 2D Materials, 2019,6(4):045018.
[67] Pappas D. Kamper K, Hopster H, Reversible transition between perpendicular and in-plane magnetization in ultrathin films[J], Physical Review Letters, 1990,64(26):3179-3182.
[68] Niu B, Su T, Francisco B A, et al., Coexistence of magnetic orders in two dimensional magnet CrI3[J], Nano Letters, 2020,20(1):553-558.
[69] Li S, Ye Z, Luo X, et al., Magnetic-field-induced quantum phase transitions in a van der Waals magnet[J], Physical Review X, 2020,10(1):011075.
[70] Mcguire M A, Clark G, Kc S, et al., Magnetic behavior and spin-lattice coupling in cleavable van der Waals layered CrCl3 crystals[J], Physical Review Materials, 2017,1(1):014001.
[71] Kezilebieke S, Huda M N, Vano V, et al., Topological superconductivity in a van der Waals heterostructure[J], Nature, 2020,588(7838):424-428.
[72] Yang S, Zhang T, Jiang C, Van der Waals magnets: material family, detection and modulation of magnetism, and perspective in spintronics[J], Advance Science, 2021,8(2):2002488.
[73] Wang X, Du K, Liu Y Y, et al., Raman spectroscopy of atomically thin two dimensional magnetic iron phosphorus trisulfide (FePS3) crystals[J], 2D Materials, 2016,3(3):031009.
[74] Liu Q Y, Wang L, Fu Y, et al., Magnetic order in XY-type antiferromagnetic monolayer CoPS3 revealed by Raman spectroscopy[J], Physical Review B, 2021,103(23):2354111-2354117.
[75] Chittari B L, Park Y, Lee D, et al., Electronic and magnetic properties of single-layer MPX3 metal phosphorous trichalcogenides[J], Physical Review B, 2016,94(18):184428
[76] Du K Z, Wang X Z, Liu Y, et al., Weak van der Waals stacking, wide-range band gap, and raman study on ultrathin layers of metal phosphorus trichalcogenides[J], ACS nano, 2016,10(2):1738-1743.
[77] Deng Y,Yu Y, Song Y, et al., Gate-tunable room-temperature ferromagnetism in two-dimensional Fe3GeTe2[J], Nature, 2018,563(7729):94-99.
[78] Tan C, Lee J, Jung S G, et al., Hard magnetic properties in nanoflake van der Waals Fe3GeTe2[J], Nature Communications, 2018,9(1):1554.
[79] Seo J, Kim D Y, An E S, Nearly room temperature ferromagnetism in a magnetic metal-rich van der Waals metal [J], Science Advances, 2020,6(3):1-9.
[80] Alahmed L, Nepal B, Macy J, et al., Magnetism and spin dynamics in room temperature van der Waals magnet Fe5GeTe2[J], 2D Materials, 2021,8(4):045030.
[81] Sivadas N, Daniels M W, Swendsen R H, et al., Magnetic ground state of semiconducting transition-metal trichalcogenide monolayers[J], Physical Review B, 2015,91(23):235425.
[82] Gong C, Kim E M, Wang Y, et al., Multiferroicity in atomic van der Waals heterostructures[J], Nature Communications, 2019,10(1):2657.
[83] Yang H, Wang F, Zhang H, et al., Solution synthesis of layered van der Waals ferromagnetic CrGeTe3 nanosheets from a non-vdW Cr2Te3 template[J], Journal of the American Chemical Society, 2020,142(9):4438-4444.
[84] Kanamaru S Y, Koizumi M, Nagai S., Synthesis and some properties of a layer-type inorganic-organic complex of FeOCl and pyridine[J], Chemistry. Letters, 1974,4(3):373-376
[85] Krimmel A, Strempfer J, Bohnenbuck B, et al., Incommensurate structure of the spin-Peierls compound TiOCl in zero and finite magnetic fields[J], Physical Review B, 2006,73(17):172413.
[86] Smaalen P S, Lukas A, Incommensurate interactions and nonconventional spin-Peierls transition in TiOBr[J], Physical Review B, 2005,72(2):020105.
[87] Angelkort J, Wölfel A, Schönleber A, et al., Observation of strong magnetoelastic coupling in a first-order phase transition of CrOCl[J], Physical Review B, 2009,80(14):144416
[88] Otrokov M M, Klimovskikh I I, Bentmann H, et al., Prediction and observation of an antiferromagnetic topological insulator[J], Nature, 2019,576(7787):416-422.
[89] Hu C, Gordon K N, Liu P, et al., A van der Waals antiferromagnetic topological insulator with weak interlayer magnetic coupling[J], Nature Communications, 2020,11(1):97.
[90] Liu C, Wang Y, Li H, et al., Robust axion insulator and Chern insulator phases in a two-dimensional antiferromagnetic topological insulator[J], Nature Materials, 2020,19(5):522-527.
[91] Zhang D, Shi M, Zhu T, et al., Topological axion states in the magnetic insulator MnBi2Te4 with the quantized magnetoelectric effect[J], Physical Review Letters, 2019,122(20):206401.
[92] Otrokov M M, Rusinov I P, Blanco-Rey M, et al., Unique thicknessdependent properties of the van der Waals interlayer antiferromagnet MnBi2Te4 Films[J], Physical Review Letters, 2019,122(10):107202.
[93] Bender S A, Duine, R A, Tserkovnyak Y, Electronic pumping of quasiequilibrium Bose-Einstein-condensed magnons[J], Physical Review Letters, 2012,108(24):246601.
[94] Brockhouse B N, Scattering of neutrons by spin waves in magnetite[J], Physical Review, 1957,106(5):859-864.
[95] Nikuni T O, Oosawa A, Tanaka H, Bose-Einstein condensation of dilute magnons in TlCuCl3[J], Physical Review Letters, 2000,84(25):5868.
[96] Demokritov S O, Demidov V. E, Dzyapko O, et al., Bose-Einstein condensation of quasi-equilibrium magnons at room temperature under pumping[J], Nature, 2006,443(7110):430-433.
[97] Uchida K, Adachi H, Kikuchi D, et al., Generation of spin currents by surface plasmon resonance[J], Nature Communications, 2015,6(6910):5910.
[98] Pershoguba S S, Banerjee S, Lashley J C, et al., Dirac magnons in honeycombferromagnets[J], Physical Review X, 2018,8(1):011010.
[99] Ghazaryan D, Greenaway M T, Wang Z, et al., Magnon-assisted tunnelling in van der Waals heterostructures based on CrBr3[J], Nature Electronics, 2018,1(6):344-349.
[100] Bass F G, Kaganov M I, Raman scattering of electromagnetic waves in ferromagnetic dielectrics [J], Soviet physics, 1960,37(5):986-988.
[101] Loudon R, The Raman effect in crystals[J], Advances in Physics,1964,13(52):423-482.
[102] Cenker J, Huang B, Suri N, et al., Direct observation of two-dimensional magnons in atomically thin CrI3[J], Nature Physics, 2020,17(1):20-25.
[103] Mccreary A, Simpson J R, Mai T T, et al., Quasi-two-dimensional magnon identification in antiferromagnetic FePS3 via magneto-Raman spectroscopy[J], Physical Review B, 2020,101(6):064416.
[104] Kim K, Lim S Y, Lee J U, et al., Suppression of magnetic ordering in XXZtype antiferromagnetic monolayer NiPS3[J], Nature Communications, 2019,10(1):345.
[105] Kim K, Lim S Y, Kim J, et al., Antiferromagnetic ordering in van der Waals 2D magnetic material MnPS3 probed by Raman spectroscopy[J], 2D Materials, 2019,6(4):041001.
[106] Sun Y J, Tan Q H, Liu X L, et al., Probing the magnetic ordering of antiferromagnetic MnPS3 by raman spectroscopy[J], Journal of Physical Chemistry Letters, 2019,10(11):3087-3093.
[107] Tian Y, Gray M J, Ji H, et al., Magneto-elastic coupling in a potential ferromagnetic 2D atomic crystal[J], 2D Materials, 2016,3(2):025035.
[108] Milosavljević A, Šolajić A, Djurdjić-Mijin S, et al., Lattice dynamics and phase transitions in Fe3−xGeTe2[J], Physical Review B, 2019,99(21):214304.
[109] Li T, Jiang S, Sivadas N, et al., Pressure-controlled interlayer magnetism in atomically thin CrI3[J], Nature Materials, 2019,18(12):1303-1308.
[110] Huang B, Cenker J, Zhang X, et al., Tuning inelastic light scattering via symmetry control in the two-dimensional magnet CrI3[J], Nature Nanotechnology, 2020,15(3):212-216.
[111] Zhang Y, Wu X, Lyu B, et al., Magnetic order-induced polarization anomaly of raman scattering in 2D magnet CrI3[J], Nano Letters, 2020,20(1):729-734.
[112] Yin T, Ulman K A, Liu S, et al., Chiral phonons and giant magneto-optical effect in CrBr3 2D magnet[J], Advance Materials, 2021,33(36):e2101618.
[113] Mccreary A, Mai T T, Utermohlen F G, et al., Distinct magneto-Raman signatures of spin-flip phase transitions in CrI3[J], Nature Communications, 2020,11(1):3879.
[114] Fleury P A, Loudon R, Scattering of light by one- and two-magnon excitations[J], Physical Review, 1968,166(2):514-530.
[115] Thuc T. Mai K G, Amber M, et al., Magnon-phonon hybridization in 2D antiferromagnet MnPSe3[J], Science Advances, 2021,7(3106):1-6.
[116] Liu S, Granados D A, Bhowmick D, et al., Direct observation of magnonphonon strong coupling in two-dimensional antiferromagnet at high magnetic fields[J], Physical Review Letters, 2021,127(9):097401.
[117] Vaclavkova D, Palit M, Wyzula J, et al., Magnon polarons in the van der Waals antiferromagnet FePS3[J], Physical Review B, 2021,104(13):1344371-1344378.
[118] Kong T, Stolze K, Timmons E I, et al., VI3-a new layered ferromagnetic semiconductor[J], Advance Materials, 2019,31(17):1808074.
[119] Tian S, Zhang J F, Li C, et al., Ferromagnetic van der Waals crystal VI3[J], Journal of the American Chemical Society, 2019,141(13):5326-5333.
[120] Doležal P, KratochvílováM, Holý V, et al., Crystal structures and phase transitions of the van der Waals ferromagnet VI3[J], Physical Review Materials, 2019,3(12):121401.
[121] Son S, Coak M J, Lee N, et al., Bulk properties of the van der Waals hard ferromagnet VI3[J], Physical Review B, 2019,99(4):041402.
[122] Liu Y, Abeykoon M, Petrovic C, Critical behavior and magnetocaloric effect in VI3[J], Physical Review Research, 2020,2(1):013013.
[123] Gati E, Inagaki Y, Kong T, et al., Multiple ferromagnetic transitions and structural distortion in the van der Waals ferromagnet VI3 at ambient and finite pressures[J], Physical Review B, 2019,100(9):094408.
[124] Djurdjic M S, Abeykoon A M, Solajic A, et al., Short-range order in VI3[J], Inorganic Chemistry, 2020,59(22):16265-16271.
[125] Wang Y M, Tian S J, Li C H, et al., Raman scattering study of twodimensional magnetic van der Waals compound VI3[J], Chinese Physics B,2020,29(5):056301.
[126] Kong T, Guo S, Ni D, et al., Crystal structure and magnetic properties of the layered van der Waals compound VBr3[J], Physical Review Materials,2019,3(8):084419.
[127] Liu L, Yang K, Wang G, et al., Two-dimensional ferromagnetic semiconductor VBr3 with tunable anisotropy[J], Journal of Materials Chemistry C, 2020,8(42):14782-14788.
[128] Robert R E, Roddy J W, The vapor pressures of vanadium chloride, vanadium chloride, vanadium bromide, and vanadium bromide by knudsen effusion[J], Inorganic Chemistry, 1964,3(60):60-63.
[129] Neumann H, Bellabarba C, Khan A, et al., Optical properties of MnIn2Se4[J], Crystal. Reseach. Technology, 1986,21(1):K21-K24
[130] Doll G, Lux-Steiner M, Bucher E, et al., Chemical vapour transport and stuctural characterization of layered MnIn2Se4 single cryatals[J], Journal of Crystal Growth, 1990,104(90):593-600.
[131] Doll G, Baumann J R, Bucher E, et al., Range structural and magnetic properties of the ternary manganese compound semiconductors MnAl2Te4, MnIn2Te4, and MnIn2Se4[J], Physica Status Solidi, 1991,126(61), 237-244.
[132] Range K, Döll G, Bucher E, et al., The crystal structure of MnIn2Se4 a ternary layered semiconductor[J], Notizen, 1991,46b:1122-1124.
[133]Haeuseler H, Reinen D, Kesper U, Materials with layered structures.VII.subsolidus phase diagram of the system MnIn2Se4-MnIn2Se4 and characterization of the layered materials MnIn2SxSe4-x by electrical measurements and diffuse reflectance spectroscopy[J], JournaI of Solid State Chemistry, 1993,106(9):501-505.
[134] Berand N, Range K J, Rietveld structure refinement of two high-pressure spinels Znln2S4 and Mnln2Se4 [J], Journal of Alloys and Compounds, 1996, 241(1):29-33.
[135] Tovar R, Quintero M Q, Bocaranda P, et al., Magnetic behaviour for the MnIn2(1-z)Ga2zSe4 alloys[J], Physica Status Solidi (b), 2000,220(8):435.
[136] Sagredoa V, Attolinic G, Magnetic properties of MnGa2Se4–MnIn2Se4 single crystal semiconductors[J], Physica B, 2002,320:407-409.
[137] Choi J Y, Jiyoun S C, Hwang Y. H, et al., Magnetic and optical properties of MnIn2Se4 single crystal[J], Journal of the Korean Physical Society, 2004,45(3):672-674.
[138] Mantilla C B, Haar V, Coaquira E, et al., Spin glass behavior in MnIn2Se4 and Zn1−xMnxIn2Se4 magnetic semiconductors[J], Journal of Magnetism and Magnetic Materials, 2004,272-276(10):1308-1309.
[139] Mantilla J T H, Coaquira E, Bindilatti A H, Experimental evidence of the spin-glass transition in the diluted magnetic semiconductor Zn1−xMnxIn2Se4[J], Journal of Physics: Condensed Matter, 2008,20(45):455211.
[140] Mantilla J B, Haar G E S, Sagredo E, et al., The structure of Zn1-xMnxIn2Se4 crystals grown by chemical vapour phase transport[J], Journal of Physics:Condensed Matter, 2004,16(21):3555-3562.
[141] Rincón C, Torrres T E, Sagredo V, et al., The fundamental absorption edge in MnIn2Se4 layer semi-magnetic semiconductor[J], Physica B: Condensed Matter, 2015,477(9):123-128.
[142] Yang J, Zhou Z, Fang J, et al., Magnetic and transport properties of a ferromagnetic layered semiconductor MnIn2Se4[J], Applied Physics Letters,2019,115(22): 032005.
[143] Fourcaudot G, Vapor phase transport and crystal growth of molybdenum trioxide and molybdenum ditelluride[J], Journal of Crystal Growth,1979,46(1):132-135.
[144] Watson A J, Lu W, Guimarães M H D, et al., Transfer of large-scale two dimensional semiconductors: challenges and developments[J], 2D Materials,2021,8(3):032001.
[145] Muratore C, Hu J J, Wang B, et al., Continuous ultra-thin MoS2 films grown by low-temperature physical vapor deposition[J], Applied Physics Letters, 2014,104(26):261604.
[146] Li X, Zhang J, Puretzky A A, et al., Isotope-engineering the thermal conductivity of two-dimensional MoS2[J], ACS nano, 2019,13(2):2481-2489.
[147] Lin G T, Zhuang H L, Luo X, et al., Tricritical behavior of the twodimensional intrinsically ferromagnetic semiconductor CrGeTe3[J], Physical Review B, 2017,95(24):245212.
[148] May A F, Calder S, Cantoni C, et al., Magnetic structure and phase stability of the van der Waals bonded ferromagnet Fe3−xGeTe2[J], Physical Review B, 2016,93(1):014411.
[149] Zhu F F, Chen W J, Xu Y, et al., Epitaxial growth of two-dimensional stanene[J], Nature Materials, 2015,14(10):1020-1025.
[150] Utama M I, Lu X., Zhan D, et al., Etching-free patterning method for electrical characterization of atomically thin MoSe2 films grown by chemical vapor deposition[J], Nanoscale, 2014,6(21):12376-12382.
[151] Novoselov K S, Castro N, Two-dimensional crystals-based heterostructures:materials with tailored properties[J], Physica Scripta, 2012,146(27): 0140061-0140066.
[152] Liu Y P, Ning B Y, Gong L C, et al., A new model to predict optimum conditions for growth of 2D materials on a substrate[J], Nanomaterials (Basel), 2019,9(7):1-14.
[153] Wang B, Zhou Q, Wang J, Theoretical simulation and design of twodimensional ferromagnetic materials[J], Chinese Science Bulletin, 2020,66(6):551-562.
[154] Von D , Juza D G, Harald schafer uber die vanadinjodide VI2 und VI3[J], Zeitschrift Anorganische Allgemeine Chemie., 1969,366(13):121-129.
[155] Guo Q, Wei Z, Xue Z, et al., Semidry release of nanomembranes for tubular origami[J], Applied Physics Letters, 2020,117(11):113106.
[156] Li Q, Bi S, Bu J, et al., Atomic layer dependence of shear modulus in a two dimensional single-crystal organic-inorganic hybrid perovskite[J], The Journal of Physical Chemistry C, 2019,123(24):15251-15257.
[157] Novoselov K S, Morozov S V, Jiang D, et al., Electric field effect in atomically thin carbon films[J], Science, 2004,306(22):666-669.
[158] Novoselov K. S, Booth T. J, Khotkevich V V, et al., Two-dimensional atomic crystals[J], PNAS, 2005,102(30):10451-10453.
[159] Huang Y, Pan Y H, Yang R, et al., Universal mechanical exfoliation of large-area 2D crystals[J], Nat Commun, 2020,11(1):2453.
[160] Hur H K, Kocabas D Y, Rogers C, et al., Nanotransfer printing by use of noncovalent surface forces: Applications to thin-film transistors that use single-walled carbon nanotube networks and semiconducting polymers[J], Applied Physics Letters, 2004,85(23):5730-5732.
[161] Jung Y, Choi M S, Nipane A, et al., Transferred via contacts as a platform for ideal two-dimensional transistors[J], Nature Electronics, 2019,2(5):187-194.
[162] Masubuchi S, Morimoto M, Morikawa S, et al., Autonomous robotic searching and assembly of two-dimensional crystals to build van der Waals superlattices[J], Nature Communications, 2018,9(1):1413.
[163] Jonathan N, Coleman M L, Arlene O, et al., Two-dimensional nanosheets produced by liquid exfoliation of layered materials[J], Science, 2011,331(4):568-571.
[164] Pizzocchero F, Gammelgaard L, Jessen B S, et al., The hot pick-up technique for batch assembly of van der Waals heterostructures[J], Nature Communications, 2016,7(1),189412.
[165] Kovalev A A, Tishchenko L A, Shashurin V D, et al., Application of X-ray diffraction methods to studying materials[J], Russian Metallurgy (Metally), 2018,2017(13):1186-1193.
[166] Shymanovich U N, M. Lu, W. Kahle, et al., Toward ultrafast time-resolved Debye-Scherrer x-ray diffraction using a laser-plasma source[J], Review of Scientific Instruments, 2009,80(8):083102.
[167] Bezirganyan P, Application of the invariance principle for the diffraction of X-rays in real crystals[J], Physica Status Solidi A, 1987,100(20):389.
[168] Fetisov G V, X-ray diffraction methods for structural diagnostics of materials: progress and achievements[J], Physics-Uspekhi, 2020,63(1):2-32.
[169] Shen Q, Expanded distorted-wave theory for phase-sensitive X-ray diffraction in single crystals[J], Physical Review Letters, 1999,83(23):4784-4787.
[170] Yi M J, Chu J H, Cullen Y S, et al., Novel X-ray diffraction microscopy technique for measuring textured grains of thin-films[J], Nuclear Instruments and Methods in Physics Research Section A, 2005,551(1):157-161.
[171] Turner J J, Huang X, Krupin O, et al., X-ray diffraction microscopy of magnetic structures[J], Physical Review Letters, 2011,107(3):033904.
[172] Yeghiazaryan A M, Gevorgyan, K. M., Atanesyan, A. K., The new principle for intensity calculation of X-rays dynamically diffracted in single crystals with defects[J], Journal of Physics: Conference Series, 2014,517(1):012032.
[173] Qiu Z Q, Bader S D., Surface magneto-optic Kerr effect[J], Review of Scientific Instruments, 2000,71(3):1243-1255.
[174] Song T, Fei Z, Yankowitz M, et al., Switching 2D magnetic states via pressure tuning of layer stacking[J], Nature Materials, 2019,18(12):1298-1302.
[175] Zhao W, Fei Z, Song T, et al., Magnetic proximity and nonreciprocal current switching in a monolayer WTe2 helical edge[J], Nature Materials, 2020,19(5):503-507.
[176] Zhong D, Seyler K L, Linpeng X, et al., Layer-resolved magnetic proximity effect in van der Waals heterostructures[J], Nature Nanotechnology, 2020,15(3):187-191.
[177] Gibertini M, Koperski M, Morpurgo A F, et al., Magnetic 2D materials and heterostructures[J], Nature Nanotechnology, 2019,14(5):408-419.
[178] Rahaman M, Rodriguez R D, Plechinger G, et al., Highly localized strain in a MoS2/Au heterostructure revealed by tip-enhanced raman spectroscopy[J], Nano Letters, 2017,17(10):6027-6033.
[179] Niu Y, Gonzalez-Abad S, Frisenda R, et al., Thickness-dependent differential reflectance spectra of monolayer and few-layer MoS2, MoSe2, WS2 and WSe2[J], Nanomaterials, 2018,8(9):1-10.
[180] Wu X, Wang X, Li H, et al., Vapor growth of WSe2/WS2 heterostructures with stacking dependent optical properties[J], Nano Research, 2019,12(12):3123-3128.
[181] Sakamoto M, Saitow K I, Field enhancement of MoS2: visualization of the enhancement and effect of the number of layers[J], Nanoscale, 2018,10(47):22215-22222.
[182] Li G, Chen X, Gan Y, et al., Raman spectroscopy evidence for dimerization and Mott collapse in α-RuCl3 under pressures[J], Physical Review Materials, 2019,3(2):023601.
[183] Sandilands L J, Tian Y, Plumb K W, et al., Scattering continuum and possible fractionalized excitations in alpha-RuCl3[J], Physical Review Letters, 2015,114(14):147201.
[184] Lemmensa P G, Grosc C, Magnetic light scattering in low-dimensional[J], Physics Reports, 2003,375 (1):1-103.
[185] Fano U, Effects of configuration interaction on intensities and phase shifts[J], Physical Review, 1961,124(6):1866-1878.
[186] Li Z, Lui C H, Cappelluti E, et al., Structure-dependent Fano resonances in the infrared spectra of phonons in few-layer graphene[J], Physical Review Letters, 2012,108(15):156801.
[187] Hisatomi R, Noguchi A, Yamazaki R, et al., Helicity-changing brillouin light scattering by magnons in a ferromagnetic crystal[J], Physical Review Letters, 2019,123(20):207401.
[188] Higuchi T, Kanda N,Tamaru H, et al., Selection rules for light-induced magnetization of a crystal with threefold symmetry: the case of antiferromagnetic NiO[J], Physical Review Letters, 2011,106(4):047401.
[189] Toth S, Lake B, Linear spin wave theory for single-Q incommensurate magnetic structures[J], Journal of Physics Condensed Matter, 2015,27(16):166002.
[190] Wu M, Li Z, Cao T, et al., Physical origin of giant excitonic and magnetooptical responses in two-dimensional ferromagnetic insulators[J], Nature Communications, 2019,10(1):2371.
[191] Choi G M, Schleife A, Cahill D G, Optical-helicity-driven magnetization dynamics in metallic ferromagnets[J], Nature Communications, 2017,8(19):15085.
[192] Seyler K L, Zhong D, Klein D R, et al., Ligand-field helical luminescence in a 2D ferromagnetic insulator[J], Nature Physics, 2017,14(3):277-281.
[193] Lin Z, Huang B, Hwangbo K, et al., Magnetism and its structural coupling effects in 2D ising ferromagnetic insulator VI3[J], Nano Letters, 2021,21(21):9180-9186.
[194] Zhu W K, Lu C K, Tong W, et al., Strong ferromagnetism induced by canted antiferromagnetic order in double perovskite iridates(La1−xSrx)2ZnIrO6[J], Physical Review B, 2015,91(14):144408.
[195] Girtu M A, Wynn C M, Fujita W, et al., Glassiness and canted antiferromagnetism in three geometrically frustrated triangular quantum Heisenberg antiferromagnets with additional Dzyaloshinskii-Moriya interaction[J], Physical Review B, 2000,61(6):4117-4130.
[196] Lyu B, Gao Y, Zhang Y, et al., Probing the Ferromagnetism and Spin Wave Gap in VI3 by Helicity-Resolved Raman Spectroscopy[J], Nano Letters, 2020,20(8):6024-6031.
[197] Song T C, Cai X H, Tu M, et al. Giant tunneling magnetoresistance in spinfilter van der Waals heterostructures[J], Science, 2018,360(15):1214-1218.
[198] Woolley J C, Lamarche A M, Lamarche G, et al., Magnetic behaviour of some Mn III2.VI4 compounds and their alloys[J], Journal of Magnetism and Magnetic Materals, 1995,150 (95):353-362.