UC Riverside

Since the discovery of graphene in 2004 a host of materials has been growing inthe 2D limit including semiconductors, superconductors, and topological insulators, all of which exhibit a range of unique properties. These crystals are defined by consisting of few- atom-thick sheets which can be stacked upon one another into a myriad of combinations of heterostructures with atomically sharp interfaces that effectively become fundamentally new quantum materials. But it wasn’t until 2017 that long-range magnetic ordering was observed in such systems. Bringing magnetism to the 2D regime similarly opens many doors. For example, magnetic anisotropy introduces novel interactions, and topological phenomena are more easily observed. In this thesis, I present experiments on magnetic van der Waals (vdW) materials that share similar properties such as perpendicular magnetic anisotropy (PMA) and the presence of topological spin textures. My main method of probing these phenomena is a scanning probe technique known as magnetic force microscopy (MFM), a 2D imaging technique which is sensitive to the stray fields of the spins within a magnetic sample. I also employ a relatively new approach to probe the interlayer exchange coupling of such magnetism using a quartz tuning fork (QTF) as a strong oscillator rotated within an external magnetic field to perform Differential Torque measurements. The results show incredible promise for a family of materials that can exhibit similar behaviors with their own unique flavors under varying circumstances. As the synthesis of vdW magnets becomes more routine, the techniques utilized in these studies help to establish a workflow for characterizing and probing the many unreal- ized magnetic materials on the horizon. Additionally, the skyrmions observed in Fe3GeTe2 pave the way for spintronic techniques and applications. Finally, the topological magnetic textures imaged from Fe-doped TaS2 provide insight and additional contribution to a rel- atively young and every growing body of knowledge in the facet of magnetically doped transition metal dichalcogenide (TMD) systems.