Multiple domain structure and symmetry types in narrow temperature and magnetic field ranges in layered Cr2Ge2Te6 crystal measured by magnetic force microscope

Intrinsic magnetism has recently been confirmed to survive in bilayer Cr2Ge2Te6. In this work, multiple domain structure and symmetry types and their transformations are firstly discovered in bulk layered Cr2Ge2Te6 crystal using a homebuilt magnetic force microscope (MFM). These transitions occur within a surprisingly narrow temperature range of 2 K and magnetic field range of 0.07 T, which colorful phenomenon hasn't been discovered in other materials but Cr2Ge2Te6. The MFM images show a series of basic domain patterns. Some of them also hasn't been found before, such as self-fitting disks and fine ladder structure within Y-connected walls. The symmetry of these magnetic domain patterns is discussed. The results not only are important in developing new magnetic domain theories but also may show some potential applications in storage depending on the future investigations. •Multiple domain structure and symmetry types and their transformations are firstly discovered in Cr2Ge2Te6 crystal.•Six kinds of domain structures are found in surprisingly narrow temperature 2 K and magnetic field 0.07 T.•Domain structures of self-fitting disks and fine ladder structure within Y-connected walls are firstly discovered.•The real-time evolution between Dots, circles, and HC cells with central dots acts like the spread of standing wave.